0001086222-21-000075 | 10-K | XBRL Viewer

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

The following is a summary of available-for-sale marketable securities held as of December 31, 2020 and 2019 (in thousands):


			Gross Unrealized				Aggregate Fair Value		Classification on Balance Sheet
	Amortized Cost								Short-Term Marketable Securities		Long-Term Marketable Securities
As of December 31, 2020			Gains		Losses

Commercial paper	$	46,931	$	13	$	(8)	$	46,936	$	46,936	$	—
Corporate bonds	1,628,462		9,482		(262)		1,637,682		607,403		1,030,279
Municipal securities	3,495		—		(6)		3,489		—		3,489
U.S. government agency obligations	435,653		329		(63)		435,919		89,951		345,968
	$	2,114,541	$	9,824	$	(339)	$	2,124,026	$	744,290	$	1,379,736

As of December 31, 2019
Certificates of deposit	$	150,000	$	—	$	—	$	150,000	$	150,000	$	—
Commercial paper	73,829		23		(7)		73,845		73,845		—
Corporate bonds	1,368,668		1,840		(378)		1,370,130		753,538		616,592

U.S. government agency obligations	369,475		80		(74)		369,481		165,623		203,858
	$	1,961,972	$	1,943	$	(459)	$	1,963,456	$	1,143,006	$	820,450

Fair Value Measurement Within Fair Value Hierarchy

The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets and liabilities as of December 31, 2020 and 2019 (in thousands):


	Total Fair Value		Fair Value Measurements at Reporting Date Using
			Level 1		Level 2		Level 3
As of December 31, 2020
Cash Equivalents and Marketable Securities:
Money market funds	$	74,417	$	74,417	$	—	$	—

Commercial paper	75,785		—		75,785		—
Corporate bonds	1,637,682		—		1,637,682		—
Municipal securities	3,489		—		3,489		—
U.S. government agency obligations	435,919		—		435,919		—
Mutual funds	19,932		19,932		—		—
	$	2,247,224	$	94,349	$	2,152,875	$	—

As of December 31, 2019
Cash Equivalents and Marketable Securities:
Money market funds	$	50,779	$	50,779	$	—	$	—
Certificates of deposit	150,000		—		150,000		—
Commercial paper	73,845		—		73,845		—
Corporate bonds	1,370,130		—		1,370,130		—

U.S. government agency obligations	369,481		—		369,481		—
Mutual funds	15,177		15,177		—		—
	$	2,029,412	$	65,956	$	1,963,456	$	—

Schedule of Contractual Maturities of Marketable Securities and Other Investment Related Assets

Contractual maturities of the Company’s available-for-sale marketable securities held as of December 31, 2020 and 2019 were as follows (in thousands):


	December 31, 2020		December 31, 2019
Due in 1 year or less	$	744,290	$	1,143,006
Due after 1 year through 5 years	1,379,736		820,450
	$	2,124,026	$	1,963,456

Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs

The following table reflects the activity for the Company’s major classes of liabilities measured at fair value using Level 3 inputs for the years ended December 31, 2020 and 2019 (in thousands):


	2020		2019
Liability:
Beginning balance	$	—	$	(6,300)

Cash paid upon achievement of milestone	—		6,300
Ending balance	$	—	$	—

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 352,917	$ 393,745
Marketable securities	745,156	1,143,249
Accounts receivable, net of reserves of $1,822 and $1,880 at December 31, 2020 and 2019, respectively	660,052	551,943
Prepaid expenses and other current assets	171,406	142,676
Total current assets	1,929,531	2,231,613
Marketable securities	1,398,802	835,384
Property and equipment, net	1,478,272	1,152,153
Operating lease right-of-use assets	793,945	758,450
Acquired intangible assets, net	234,724	179,431
Goodwill	1,674,371	1,600,265
Deferred income tax assets	106,918	76,528
Other assets	147,567	173,062
Total assets	7,764,130	7,006,886
Current liabilities:
Accounts payable	118,546	138,946
Accrued expenses	380,468	334,861
Deferred revenue	76,600	71,223
Operating lease liabilities	154,801	139,463
Other current liabilities	27,755	8,843
Total current liabilities	758,170	693,336
Deferred revenue	5,262	4,368
Deferred income tax liabilities	37,458	29,187
Convertible senior notes	1,906,707	1,839,791
Operating lease liabilities	715,404	692,181
Other liabilities	89,833	90,065
Total liabilities	3,512,834	3,348,928
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.01 par value; 5,000,000 shares authorized; 700,000 shares designated as Series A Junior Participating Preferred Stock; no shares issued or outstanding	0	0
Common stock, $0.01 par value; 700,000,000 shares authorized; 162,709,720 and 162,000,843 shares issued and outstanding at December 31, 2020 and 2019, respectively	1,627	1,620
Additional paid-in capital	3,664,820	3,653,486
Accumulated other comprehensive loss	(20,201)	(45,144)
Retained earnings	605,050	47,996
Total stockholders’ equity	4,251,296	3,657,958
Total liabilities and stockholders’ equity	$ 7,764,130	$ 7,006,886

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 557,054	$ 478,035	$ 298,373
Other comprehensive income (loss):
Foreign currency translation adjustments	19,629	(1,020)	(27,585)
Change in unrealized gain on investments, net of income tax provision of $2,720, $666 and $200 for the years ended December 31, 2020, 2019 and 2018, respectively	5,314	4,788	603
Other comprehensive income (loss)	24,943	3,768	(26,982)
Comprehensive income	$ 581,997	$ 481,803	$ 271,391

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Quarterly Financial Results (unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

Schedule of Unaudited Quarterly Financial Results


(in thousands, except per share data)	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Year ended December 31, 2020:
Revenue	$	764,302	$	794,715	$	792,845	$	846,287
Cost of revenue (exclusive of amortization of acquired intangible assets)	268,582		276,804		283,439		303,847
Net income	123,146		161,915		158,623		113,370
Basic net income per share	0.76		1.00		0.97		0.70
Diluted net income per share	0.75		0.98		0.95		0.68
Year ended December 31, 2019:
Revenue	$	706,508	$	705,074	$	709,912	$	772,123
Cost of revenue (exclusive of amortization of acquired intangible assets)	240,743		242,193		246,938		257,750
Net income	107,130		113,915		137,890		119,100
Basic net income per share	0.66		0.70		0.85		0.74
Diluted net income per share	0.65		0.69		0.84		0.73

Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable and Accrued Liabilities, Current [Abstract]
Payroll and other related benefits	$ 218,588	$ 190,721
Bandwidth and co-location	67,170	65,213
Income tax payable	50,812	40,337
Property, use and other taxes	35,390	30,904
Professional service fees	2,245	1,775
Other accrued expenses	6,263	5,911
Total	$ 380,468	$ 334,861

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Cash Flows [Abstract]
Income tax refund received	$ 17,491	$ 3,731	$ 18,501
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	352,917	393,745	1,036,455
Restricted cash	549	401	532
Cash, cash equivalents and restricted cash	$ 353,466	$ 394,146	$ 1,036,987

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,520,090	$ 3,031,063
Accumulated depreciation and amortization	(2,041,818)	(1,878,910)
Property and equipment, net	1,478,272	1,152,153
Computer and networking equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,847,717	1,469,293
Purchased software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	95,662	90,450
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	71,119	65,683
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	40,235	38,178
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	230,423	235,279
Internal-use software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,234,934	$ 1,132,180
Minimum \| Computer and networking equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Minimum \| Purchased software
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Minimum \| Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	1 year
Minimum \| Office equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Minimum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	1 year
Minimum \| Internal-use software
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	2 years
Maximum \| Computer and networking equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	7 years
Maximum \| Purchased software
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	10 years
Maximum \| Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	7 years
Maximum \| Office equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Maximum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	15 years
Maximum \| Internal-use software
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	7 years

Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs	$ 67,153	$ 52,059	$ 46,493
Capitalization of interest expense	(4,330)	(6,201)	(4,533)
Total interest expense	69,120	49,364	43,202
Credit Agreement
Debt Instrument [Line Items]
Interest on debt instruments	548	513	368
Convertible Debt \| 2025 Notes
Debt Instrument [Line Items]
Interest on debt instruments	1,437	1,436	874
Convertible Debt \| 2027 Notes
Debt Instrument [Line Items]
Interest on debt instruments	$ 4,312	$ 1,557	$ 0

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Stock Based Compensation Expense

The following table summarizes the components of total stock-based compensation expense included in the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Cost of revenue	$	24,829	$	22,479	$	21,892
Research and development	48,855		49,685		44,034
Sales and marketing	65,257		62,150		64,373
General and administrative	58,470		52,826		53,514
Total stock-based compensation	197,411		187,140		183,813
Provision for income taxes	(62,153)		(51,177)		(48,502)
Total stock-based compensation, net of taxes	$	135,258	$	135,963	$	135,311

Schedule of Assumptions Used

The grant-date fair values of awards granted under the 1999 ESPP during the years ended December 31, 2020, 2019 and 2018 were estimated using the Black-Scholes option pricing model with the following weighted-average assumptions:


	2020		2019		2018
Expected term (in years)	0.5		0.5		0.5
Risk-free interest rate	0.7	%	2.3	%	1.9	%
Expected volatility	30.4	%	29.6	%	31.2	%
Dividend yield	—	%	—	%	—	%

The grant-date fair values of the TSR-based RSUs granted during the years ended December 31, 2020, 2019 and 2018 were estimated using a Monte Carlo simulation model with the following assumptions:


	2020		2019		2018
Expected term (in years)	3.0		3.0		3.0
Risk-free interest rate	0.7	%	2.5	%	2.3	%
Akamai historical share price volatility	28.2	%	32.8	%	35.5	%
Average volatility of peer-company share price	28.9	%	27.0	%	26.3	%

Schedule of Summary of Stock Option Activity

The following table summarizes stock option activity during the year ended December 31, 2020:


	Shares (in thousands)	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2020	20	$	26.23
Exercised	(14)	32.85


Outstanding at December 31, 2020	6	$	11.60	1.09	$	595
Exercisable at December 31, 2020	6	$	11.60	1.09	$	595
Vested or expected to vest December 31, 2020	6	$	11.60	1.09	$	595

Schedule Of Deferred Stock Units Activity

The following table summarizes the DSU activity for the year ended December 31, 2020:


	Units (in thousands)	Weighted Average Grant Date Fair Value
Outstanding at January 1, 2020	99	$	57.50
Granted	24	100.58
Vested and distributed	(9)	76.62
Outstanding at December 31, 2020	114	$	65.09

Schedule of Restricted Stock Units by Type

The following table summarizes the different types of restricted stock units ("RSUs") granted by the Company during the year ended December 31, 2020 (in thousands):


			December 31, 2020
RSUs with service-based vesting conditions			2,223
RSUs with market-based vesting conditions			91
RSUs with performance-based vesting conditions			396
Total			2,710

Schedule of Restricted Stock Units Activity

The following table summarizes the RSU activity for the year ended December 31, 2020:


	Units (in thousands)	Weighted Average Grant Date Fair Value
Outstanding at January 1, 2020	5,073	$	70.43
Granted	2,710	92.42
Vested	(2,881)	69.04
Forfeited	(346)	75.55
Outstanding at December 31, 2020	4,556	$	83.96

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2020

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Prepaid income taxes	$	30,682	$	26,143
Prepaid sales and other taxes	24,034		16,213
Prepaid equipment and software maintenance	15,526		18,114
Deferred commissions	54,516		45,009
Other prepaid expenses	26,187		19,593
Other current assets	20,461		17,604
Total	$	171,406	$	142,676

Incremental Costs to Obtain a Contract with a Customer

The following table summarizes the deferred costs associated with obtaining customer contracts, specifically commission and incentive payments, as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Deferred costs included in prepaid and other current assets	$	54,516	$	45,009
Deferred costs included in other assets	23,200		25,698
Total deferred costs	$	77,716	$	70,707

During the years ended December 31, 2020, 2019 and 2018, the Company recognized $61.7 million, $44.3 million and $45.0 million, respectively, of amortization expense related to deferred commissions.

Prepaid Expenses and Other Current Assets - Deferred Cost (Details) - Commission and Incentive Payments - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Capitalized Contract Cost [Line Items]
Deferred costs associated with obtaining customer contracts	$ 77,716	$ 70,707
Other Current Assets
Capitalized Contract Cost [Line Items]
Deferred costs associated with obtaining customer contracts	54,516	45,009
Other Assets
Capitalized Contract Cost [Line Items]
Deferred costs associated with obtaining customer contracts	$ 23,200	$ 25,698

Stockholders' Equity (Details) - USD ($) $ in Thousands, shares in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 30, 2018	Feb. 29, 2016
Class of Stock [Line Items]
Amount of common stock repurchases authorized					$ 1,100,000	$ 1,000,000
Stock repurchase authorized amount increase	$ 416,700
Remaining amount available for future purchases of shares under approved repurchase program.	$ 750,000	$ 571,900
Value of shares repurchased during period		$ 193,588	$ 334,519	$ 750,000
Common Stock
Class of Stock [Line Items]
Repurchases of common stock (in shares)		2.0	4.0	10.2
Value of shares repurchased during period		$ 193,600	$ 334,500	$ 750,000

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax unrecognized compensation cost	$ 274.5
Weighted average period for recognizing compensation cost (in years)	1 year 7 months 6 days
Closing stock price (in dollars per share)	$ 104.99
In the money options exercisable (in shares)	6,371,000,000
Capitalized Internal Use Software
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional stock based compensation	$ 29.6	$ 30.6	$ 25.2
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Expiration period	10 years
Total pre-tax intrinsic value of options exercised	$ 1.0	$ 3.9	$ 8.2
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of equity instruments other than options granted (in dollars per share)	$ 32.30	$ 20.90	$ 15.29
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of equity instruments other than options granted (in dollars per share)	$ 100.58
Each DSU receives this number of shares of common stock upon vesting (in whole numbers)	1
Holder elect to defer vested shares period, minimum (in years)	1 year
Holder elect to defer vested shares period, maximum (in years)	10 years
The amount typically vested by anniversary grant date (percentage)	100.00%
Director's minimum period of service before vesting accelerates (in years)	1 year
Total pre-tax intrinsic value end of year	$ 0.9	$ 7.7	$ 3.0
Total fair value of vested and distributed	$ 0.7	4.9	1.8
Unvested deferred stock units (in shares)	23,908
Aggregate intrinsic value	$ 2.5
Deferred Stock Units \| Director Vesting Acceleration
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	100.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of equity instruments other than options granted (in dollars per share)	$ 92.42
Total pre-tax intrinsic value end of year	$ 192.5	189.4	173.6
Total fair value of vested and distributed	198.9	$ 195.5	$ 178.3
Aggregate intrinsic value	$ 478.5
Weighted average contractual remaining life (in years)	1 year 6 months
Each RSU receives this number of shares of common stock upon vesting	1
Restricted stock unit vesting provision, minimum (in years)	3 years
Restricted stock unit vesting provision, maximum (in years)	4 years
Number of equity instruments other than options unvested (in shares)	4,600,000
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan (in shares)	21,500,000
Common stock available for grant (in shares)	6,500,000
2009 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for grant (in shares)	3,800,000
1999 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum amount of shares available for issuance (in shares)	1,500,000
Aggregate amount of shares available, maximum (in shares)	20,000,000.0
Discount on fair market value for purchase of stock (in percentage)	15.00%
Share purchase interval term (in months)	6 months
Issuance of common stock under employee stock purchase plan (in shares)	700,000	900,000	1,000,000.0
Weighted average purchase price (in dollars per share)	$ 80.71	$ 61.04	$ 52.04
Total cash proceeds from shares purchased	$ 58.4	$ 53.7	$ 50.7
Amount withheld from employees for future purchases	$ 5.9

Leases - Lease Maturity (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Real Estate Arrangements
Lessee, Lease, Description [Line Items]
2021	$ 80,787
2022	83,863
2023	79,445
2024	70,967
2025	66,209
Thereafter	473,558
Total lease payments	854,829
Less: imputed interest	162,588
Total lease liabilities	692,241
Co-location Arrangements
Lessee, Lease, Description [Line Items]
2021	73,540
2022	36,805
2023	23,396
2024	16,815
2025	10,775
Thereafter	25,208
Total lease payments	186,539
Less: imputed interest	8,575
Total lease liabilities	$ 177,964

Nature of Business and Basis of Presentation (Details) server in Thousands	12 Months Ended
	Dec. 31, 2020 country server segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of servers (more than) \| server	325
Number of countries with networks \| country	130
Number of operating segments \| segment	1

Goodwill and Acquired Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 538,899	$ 442,326
Accumulated Amortization	(304,175)	(262,895)
Net Carrying Amount	234,724	179,431
Completed technologies
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	172,346	153,722
Accumulated Amortization	(111,435)	(94,088)
Net Carrying Amount	60,911	59,634
Customer-related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	358,032	279,684
Accumulated Amortization	(186,733)	(163,155)
Net Carrying Amount	171,299	116,529
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	373	830
Accumulated Amortization	(77)	(529)
Net Carrying Amount	296	301
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,658	7,600
Accumulated Amortization	(5,440)	(4,633)
Net Carrying Amount	2,218	2,967
Acquired license rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	490	490
Accumulated Amortization	(490)	(490)
Net Carrying Amount	$ 0	$ 0

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Stock Repurchase Program In February 2016, the board of directors authorized a $1.0 billion share repurchase program that was effective from February 2016 through December 2018. In March 2018, the Company announced that its board of directors had increased its share repurchase authorization by $416.7 million, such that the amount that was authorized and available for repurchase in 2018 was $750.0 million. Subsequently, effective November 2018, the board of directors authorized a $1.1 billion repurchase program through December 2021. The Company's goals for the share repurchase programs are to offset some or all of the dilution created by its employee equity compensation programs and provide the flexibility to return capital to shareholders as business and market conditions warrant. During the years ended December 31, 2020, 2019 and 2018, the Company repurchased 2.0 million, 4.0 million and 10.2 million shares, respectively, of its common stock for $193.6 million, $334.5 million and $750.0 million, respectively, pursuant to the repurchase programs described above. As of December 31, 2020, the Company had $571.9 million available for future purchases of shares under the current repurchase program. The board of directors authorized the retirement of all the outstanding shares of its treasury stock as of each of December 31, 2020, 2019 and 2018. The retired shares were returned to the number of authorized but unissued shares of the Company's common stock, and the retirement was recorded to additional paid-in capital.

Leases (Tables)

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Components of Lease Expense

The following table is a summary of the Company’s operating lease costs for the years ended December 31, 2020 and 2019 (in thousands):


	December 31, 2020						December 31, 2019
	Real Estate Arrangements		Co-location Arrangements		Total		Real Estate Arrangements		Co-location Arrangements		Total
Operating lease cost	$	83,574	$	113,554	$	197,128	$	63,893	$	96,020	$	159,913
Short-term lease cost	229		15,620		15,849		111		14,301		14,412
Variable lease cost	21,235		34,259		55,494		15,610		23,524		39,134
Sublease income	(22,064)		—		(22,064)		(5,119)		—		(5,119)
Total operating lease costs	$	82,974	$	163,433	$	246,407	$	74,495	$	133,845	$	208,340

Maturities of Operating Lease Liabilities

Maturities of operating lease liabilities as of December 31, 2020 were as follows (in thousands):


	Real Estate Arrangements		Co-location Arrangements
2021	$	80,787	$	73,540
2022	83,863		36,805
2023	79,445		23,396
2024	70,967		16,815
2025	66,209		10,775
Thereafter	473,558		25,208
Total lease payments	854,829		186,539
Less: imputed interest	162,588		8,575
Total lease liabilities	$	692,241	$	177,964

Prepaid Expenses and Other Current Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Commissions
Capitalized Contract Cost [Line Items]
Amortization expense related to deferred commissions	$ 61.7	$ 44.3	$ 45.0

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

As of December 31, 2020, the Company had long-term commitments for bandwidth usage with various networks and ISPs. Additionally, as of December 31, 2020, the Company had entered into purchase orders with various vendors. The minimum future commitments as of December 31, 2020 were as follows (in thousands):


	Bandwidth Commitments		Purchase Order Commitments
2021	$	95,923	$	231,059
2022	19,046		22,014
2023	4,186		9,640
2024	120		3,931
2025	120		—
Thereafter	100		—
Total	$	119,495	$	266,644

Legal Matters

The Company is party to various litigation matters that management considers routine and incidental to its business. Management does not expect the results of any of these routine actions to have a material effect on the Company’s business, results of operations, financial condition or cash flows.

In July 2016, as part of the resolution of a patent infringement lawsuit filed by the Company against Limelight Networks, Inc. (“Limelight”) in 2006, the Company entered into an agreement that requires Limelight to pay the Company $54.0 million in 12 equal installments over three years, beginning in August 2016. During the years ended December 31, 2019 and 2018, the Company received $9.0 million and $18.0 million, respectively, under this agreement. Substantially all of the amounts received

were recorded as a gain contingency in the year the cash was received, which reduced general and administrative expenses in the consolidated statements of income, with the remaining as interest income.

In April 2018, as part of the resolution of multiple existing lawsuits between Limelight and the Company, including in the U.S. District Court for the Eastern District of Virginia and in the U.S. District Court for the District of Massachusetts, the parties entered into an agreement to settle the cases and request that the U.S. Patent Trial and Appeal Board terminate certain proceedings related to patents at issue in the litigation. The Company recorded a $14.9 million charge in the second quarter of 2018, which is included in general and administrative expenses in the consolidated statement of income for the year ended December 31, 2018, related to this settlement.

Indemnification

The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these agreements, the Company agrees to indemnify, hold harmless and reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company's business partners, vendors or customers, in connection with its provision of its services. Generally, these obligations are limited to claims relating to infringement of a patent, copyright or other intellectual property right or the Company’s negligence, willful misconduct or violation of law. Subject to applicable statutes of limitation, the term of each of these indemnification agreements is generally perpetual from the time of execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited; however, the Company carries insurance that covers certain third-party claims relating to its services and activities and that could limit the Company’s exposure in that respect.

The Company has agreed to indemnify each of its officers and directors, or employees who serve as officers or directors of our subsidiaries at management's request, during his or her lifetime for certain events or occurrences that happen by reason of the fact that the officer or director is or was or has agreed to serve as an officer or director of the Company. The Company has director and officer insurance policies that may limit its exposure and may enable the Company to recover a portion of certain future amounts paid.

To date, the Company has not encountered material costs as a result of such indemnification obligations and has not accrued any related liabilities in its financial statements. In assessing whether to establish an accrual, the Company considers such factors as the degree of probability of an unfavorable outcome and the ability to make a reasonable estimate of the amount of loss.

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Components of Income Before Tax

The components of income before provision for income taxes were as follows for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
U.S.	$	45,074	$	24,253	$	(27,379)
Foreign	571,008		508,228		370,468
Income before provision for income taxes	$	616,082	$	532,481	$	343,089

Schedule of Provision for Income Tax

The provision for income taxes consisted of the following for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Current tax (benefit) provision:
Federal	$	(1,765)	$	(22,704)	$	(29,982)
State	5,346		3,835		8,085
Foreign	76,162		71,286		64,274
Deferred tax (benefit) provision:
Federal	(19,845)		(13,987)		5,954
State	(14,509)		(12,212)		701
Foreign	(6,023)		4,968		(7,140)
Change in valuation allowance	6,556		22,164		2,824
Total	$	45,922	$	53,350	$	44,716

Schedule of Difference Between Effective and Statutory

The Company’s effective tax rate differed from the U.S. federal statutory tax rate as follows for the years ended December 31, 2020, 2019 and 2018:


	2020		2019		2018
U.S. federal income tax rate	21.0	%	21.0	%	21.0	%
State taxes	1.0		1.0		1.2
Stock-based compensation	(0.6)		0.3		1.0
U.S. federal, state and foreign research and development credits	(4.4)		(6.0)		(7.6)
Foreign earnings	(7.7)		(6.1)		(6.0)

Nondeductible (nontaxable) foreign items	(0.4)		0.7		0.4
Impact of U.S. Tax Cuts and Jobs Act, net	—		—		(0.8)


Release of uncertain tax position reserve	(0.9)		(5.9)		(1.9)

Intercompany sale of intellectual property	0.2		1.9		3.3
Valuation allowance	1.1		4.2		0.8
Other	(1.8)		(1.1)		1.6
	7.5	%	10.0	%	13.0	%

Net Deferred Tax and Valuation Allowance

The components of the net deferred tax assets and liabilities and the related valuation allowance as of December 31, 2020 and 2019 were as follows (in thousands):


	2020		2019
Accrued bonus	$	25,480	$	25,487
Deferred revenue	11,146		3,874

Operating lease liability	141,212		147,375
Stock-based compensation	23,629		20,606
NOLs	25,255		25,851
Unrealized losses	—		1,529
Tax credit carryforwards	110,254		87,305

Convertible senior notes interest	20,953		22,506
Other	11,531		12,501
Deferred tax assets	369,460		347,034
Depreciation and amortization	(6,974)		(16,896)

Acquired intangible assets	(59,128)		(51,758)

Operating lease right-of-use asset	(127,524)		(132,949)
Deferred commissions	(14,952)		(14,843)
Internal-use software development costs capitalized	(58,820)		(57,201)

Deferred tax liabilities	(267,398)		(273,647)
Valuation allowance	(32,602)		(26,046)
Net deferred tax assets	$	69,460	$	47,341

Schedule of Operating Loss Carryforwards

The table below summarizes the Company's NOL and tax credit carryforwards in federal, state and foreign jurisdictions as of December 31, 2020 and 2019 (in thousands, except for years):


	2020		2019		Expirations at Various Dates Through:
NOL carryforwards:
Federal	$	59,200	$	87,500	2037
State	24,800		20,500		2040
Foreign	40,800		11,600		—
Federal and state research and development tax credit and other credit carryforwards	132,800		88,570		2034

Unrecognized Tax Benefits

The following is a roll forward of the Company’s unrecognized tax benefits for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Balance at beginning of year	$	27,359	$	64,892	$	85,845
Gross increases – tax positions of prior periods	2,539		74		2,704
Gross increases – current period tax positions	1,946		2,006		3,021
Gross decreases – tax positions of prior periods	(3,540)		(5,201)		(15,287)
Gross decreases – lapse of applicable statute of limitations	(4,199)		(28,672)		(6,186)
Gross decreases – settlements	—		(5,740)		(5,205)
Balance at end of year	$	24,105	$	27,359	$	64,892

Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment per unit value, minimum	$ 1,000								$ 1,000
Property, plant and equipment, estimated useful life									1 year
Property, software and equipment depreciation, amortization expense									$ (436,300,000)	$ (402,100,000)	$ (401,200,000)
Net income	$ 113,370,000	$ 158,623,000	$ 161,915,000	$ 123,146,000	$ 119,100,000	$ 137,890,000	$ 113,915,000	$ 107,130,000	$ 557,054,000	$ 478,035,000	$ 298,373,000
Basic (in dollars per share)	$ 0.70	$ 0.97	$ 1.00	$ 0.76	$ 0.74	$ 0.85	$ 0.70	$ 0.66	$ 3.43	$ 2.94	$ 1.78
Network Assets
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)										5 years	4 years
Network Assets \| Change In Average Useful Lives
Property, Plant and Equipment [Line Items]
Property, software and equipment depreciation, amortization expense									$ 22,900,000	$ 31,500,000
Net income									$ 19,200,000	$ 26,100,000
Basic (in dollars per share)									$ 0.12	$ 0.16

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Stock-Based Compensation - Schedule of Restricted Stock Units by Type (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total restricted stock units vesting conditions granted (in shares)	2,710
Service-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units vesting conditions granted (in shares)	2,223
Market-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted with performance based vesting (in shares)	91
Market-and performance-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted with performance based vesting (in shares)	396

Summary of Significant Accounting Policies - Equity Method Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Loss from equity method investment	$ (13,106)	$ (1,096)	$ 0
Operating Income (Loss)	$ (658,534)	(548,918)	$ (362,499)
GO-NET
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
Equity method investment	$ 21,600
Loss from equity method investment	(13,100)	(1,100)
Impairment loss	11,000
Revenue from related party	11,100	$ 11,600
GO-NET \| GO-NET
Schedule of Equity Method Investments [Line Items]
Operating Income (Loss)	$ 2,100

Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2020

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule of Accumulated Other Comprehensive Loss

The following table summarizes the changes in accumulated other comprehensive loss, which is reported as a component of stockholders' equity, for the years ended December 31, 2020 and 2019 (in thousands):


	Foreign Currency Translation		Net Unrealized Gains on Investments		Total
Balance as of January 1, 2019	$	(51,904)	$	2,992	$	(48,912)
Other comprehensive (loss) income	(1,020)		4,788		3,768
Balance as of December 31, 2019	(52,924)		7,780		(45,144)
Other comprehensive income	19,629		5,314		24,943
Balance as of December 31, 2020	$	(33,295)	$	13,094	$	(20,201)

Accounts Receivable - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 661,874	$ 553,823
Allowance for current expected credit losses and other reserves	(1,822)	(1,880)	$ (1,534)	$ (1,281)
Accounts receivable, net	660,052	551,943
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	473,474	396,204
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 188,400	$ 157,619

Business Acquisitions (Details) - USD ($)			1 Months Ended				12 Months Ended
Business Acquisitions (Details) - USD ($)	Nov. 10, 2019	Nov. 01, 2019	Feb. 28, 2021	Oct. 31, 2020	Feb. 29, 2020	Jan. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Acquisition related costs							$ 5,600,000	$ 1,900,000	$ 1,000,000.0
Allocation of the purchase consideration:
Goodwill							1,674,371,000	1,600,265,000	1,487,404,000
Payments To Acquire Assets							$ 36,376,000	$ 0	$ 0
Instart Logic
Allocation of the purchase consideration:
Payments To Acquire Assets					$ 36,400,000
Customer-related intangible assets \| Instart Logic
Allocation of the purchase consideration:
Useful life					17 years
Inverse, Inc. \| Subsequent Event
Business Acquisition [Line Items]
Cash transferred			$ 20,000,000.0
Asavie
Business Acquisition [Line Items]
Cash transferred				$ 155,000,000.0
Allocation of the purchase consideration:
Total purchase consideration				154,952,000
Cash				26,847,000
Accounts receivable				14,002,000
Prepaid expenses and other current assets				995,000
Property and equipment				2,274,000
Operating lease right-of-use assets				6,104,000
Identifiable intangible assets				58,070,000
Goodwill				70,228,000
Other assets				395,000
Total assets acquired				178,915,000
Accounts payable				(951,000)
Accrued liabilities				(5,926,000)
Deferred revenue				(3,136,000)
Operating lease liabilities				(6,104,000)
Deferred income tax liabilities				(6,965,000)
Other liabilities				(881,000)
Total liabilities assumed				(23,963,000)
Net assets acquired				154,952,000
Goodwill expected tax deductible amount				0
Gross carrying amount of intangible assets				$ 58,070,000
Weighted average useful life				10 years 9 months 18 days
Asavie \| Completed technologies
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 17,300,000
Weighted average useful life				10 years 1 month 6 days
Asavie \| Customer-related intangible assets
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 40,400,000
Weighted average useful life				11 years 1 month 6 days
Asavie \| Trademarks
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 100,000
Weighted average useful life				10 months 24 days
Asavie \| Non-compete agreements
Allocation of the purchase consideration:
Gross carrying amount of intangible assets				$ 270,000
Weighted average useful life				2 years 10 months 24 days
ChameleonX
Business Acquisition [Line Items]
Cash transferred	$ 11,900,000
Allocation of the purchase consideration:
Identifiable intangible assets	6,100,000
Goodwill	7,100,000
Goodwill expected tax deductible amount	$ 7,100,000
Weighted average useful life	7 years 1 month 6 days
Exceda
Business Acquisition [Line Items]
Cash transferred		$ 32,700,000
Allocation of the purchase consideration:
Identifiable intangible assets		16,500,000
Goodwill		14,700,000
Goodwill expected tax deductible amount		$ 14,700,000
Weighted average useful life		8 years 1 month 6 days
Indemnification asset		$ 20,000,000.0
Janrain, Inc.
Business Acquisition [Line Items]
Cash transferred						$ 123,600,000
Allocation of the purchase consideration:
Total purchase consideration						123,632,000
Cash						2,223,000
Accounts receivable						7,318,000
Prepaid expenses and other current assets						838,000
Identifiable intangible assets						26,930,000
Goodwill						92,188,000
Deferred tax asset						12,622,000
Other assets						87,000
Total assets acquired						142,206,000
Accounts payable						(1,642,000)
Deferred revenue						(14,336,000)
Other liabilities						(2,596,000)
Total liabilities assumed						(18,574,000)
Net assets acquired						123,632,000
Goodwill expected tax deductible amount						45,700,000
Gross carrying amount of intangible assets						$ 26,930,000
Weighted average useful life						11 years 9 months 18 days
Janrain, Inc. \| Completed technologies
Allocation of the purchase consideration:
Gross carrying amount of intangible assets						$ 9,000,000
Weighted average useful life						7 years 10 months 24 days
Janrain, Inc. \| Customer-related intangible assets
Allocation of the purchase consideration:
Gross carrying amount of intangible assets						$ 17,700,000
Weighted average useful life						13 years 10 months 24 days
Janrain, Inc. \| Trademarks
Allocation of the purchase consideration:
Gross carrying amount of intangible assets						$ 200,000
Weighted average useful life						1 year 10 months 24 days
Janrain, Inc. \| Non-compete agreements
Allocation of the purchase consideration:
Gross carrying amount of intangible assets						$ 30,000
Weighted average useful life						1 year 10 months 24 days

Net Income per Share - Schedule of Components (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income	$ 113,370	$ 158,623	$ 161,915	$ 123,146	$ 119,100	$ 137,890	$ 113,915	$ 107,130	$ 557,054	$ 478,035	$ 298,373
Denominator:
Shares used for basic net income per share (in shares)									162,490	162,706	167,312
Effect of dilutive securities:
Stock options (in shares)									31	68	132
RSUs and deferred stock units (in shares)									1,819	1,799	1,744
Convertible senior notes (in shares)									873	0	0
Warrants related to issuance of convertible senior notes (in shares)									0	0	0
Shares used for diluted net income per share (in shares)									165,213	164,573	169,188
Basic net income per share (in dollars per share)	$ 0.70	$ 0.97	$ 1.00	$ 0.76	$ 0.74	$ 0.85	$ 0.70	$ 0.66	$ 3.43	$ 2.94	$ 1.78
Diluted net income per share (in dollars per share)	$ 0.68	$ 0.95	$ 0.98	$ 0.75	$ 0.73	$ 0.84	$ 0.69	$ 0.65	$ 3.37	$ 2.90	$ 1.76

Business Acquisitions

12 Months Ended

Dec. 31, 2020

Business Combinations [Abstract]

Business Acquisitions

Acquisitions

Acquisition-related costs were $5.6 million, $1.9 million and $1.0 million during the years ended December 31, 2020, 2019 and 2018, respectively, and are included in general and administrative expense in the consolidated statements of income. Pro forma results of operations for the acquisitions completed in the years ended December 31, 2020 and 2019 have not been presented because the effects of the acquisitions, individually and in the aggregate, are not material to the Company's consolidated financial results. Revenue and earnings attributable to acquired operations since the dates of their acquisitions are included in the Company's consolidated statements of income and not presented separately because they are not material.

Inverse

In February 2021, the Company acquired Inverse, Inc., a Montreal-based company, for approximately $20.0 million. The allocation of the purchase price has not been finalized as of the filing of these financial statements. The acquisition is intended

to enhance the Company's enterprise security capabilities and expand its portfolio of zero trust and secure access service edge solutions for the internet of things.

2020 Acquisitions

Asavie

In October 2020, the Company acquired all outstanding stock of Asavie Technologies Limited ("Asavie"), a privately-funded company headquartered in Dublin, Ireland, for $155.0 million in cash. The allocation of the purchase price has not been finalized as of the filing of these financial statements. Asavie operates a global platform for managing the security, performance and access policies for mobile and internet-connected devices; its solutions will become part of Akamai’s security and personalization services product line.

The following table presents the preliminary allocation of the purchase price for Asavie (in thousands):


Total purchase consideration	$	154,952

Allocation of the purchase consideration:
Cash	$	26,847
Accounts receivable	14,002
Prepaid expenses and other current assets	995
Property and equipment	2,274
Operating lease right-of-use assets	6,104
Identifiable intangible assets	58,070
Goodwill	70,228
Other assets	395
Total assets acquired	178,915
Accounts payable	(951)
Accrued liabilities	(5,926)
Deferred revenue	(3,136)
Operating lease liabilities	(6,104)
Deferred income tax liabilities	(6,965)
Other liabilities	(881)
Total liabilities assumed	(23,963)
Net assets acquired	$	154,952

The value of the goodwill can be attributed to a number of business factors, including a trained technical and sales workforce and cost synergies expected to be realized. None of goodwill related to the acquisition of Asavie is expected to be deductible for tax purposes.

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	17,300	10.1
Customer-related intangible assets	40,400		11.1
Trademarks	100		0.9
Non-compete agreements	270		2.9
Total	$	58,070

The total weighted average amortization period for the intangible assets acquired from Asavie is 10.8 years. The intangible assets are being amortized based upon the pattern in which the economic benefits of the intangible assets are being utilized.

Instart Logic

In February 2020, the Company acquired certain assets from Instart Logic, Inc., a provider of cloud solutions for improving web and mobile application performance, for $36.4 million in cash. The purchase price was primarily allocated to a customer-related intangible asset that will be amortized over 17 years in a pattern that matches expense with expected economic benefits.

2019 Acquisitions

ChameleonX

In November 2019, the Company acquired ChameleonX, Ltd. ("ChameleonX"), an Israel-based company with a solution designed to detect when a website contains or links to malware that causes end user data to be compromised, for $11.9 million in cash. The acquisition is expected to further strengthen the Company's security solutions portfolio. The Company allocated $7.1 million of the cost of the acquisition to goodwill and $6.1 million to a technology-related identifiable intangible asset with an average useful life of 7.1 years. The value of the goodwill is primarily attributable to synergies related to the integration of ChameleonX technology onto the Company's platform as well as a trained technical workforce. The total amount of goodwill related to the acquisition of ChameleonX expected to be deductible for tax purposes is $7.1 million. The Company finalized its allocation of purchase price in the fourth quarter of 2020, which did not result in a material change to the preliminary allocation.

Exceda

On November 1, 2019, in a series of stock and asset purchase transactions, the Company acquired the operations of a group of companies known as Exceda, a vendor of content delivery network and web security services and, collectively, the Company's largest channel partner in Latin America, for $32.7 million in cash. The acquisition is expected to enable the Company to expand its Latin America business more quickly, better support existing and new partners and improve experiences for more customers. The Company allocated $14.7 million of the cost of the acquisition to goodwill and $16.5 million to identifiable intangible assets, primarily customer-related. The total weighted average useful life of the intangible assets acquired from Exceda is 8.1 years. The value of the goodwill is primarily attributable to synergies related to the scale of the combined teams as well as Exceda's trained technical workforce. The total amount of goodwill related to the acquisition of Exceda expected to be deductible for tax purposes is $14.7 million.

The Company acquired various obligations as part of the acquisition for which it is indemnified. The total obligations recorded, with corresponding indemnification asset, totaled $20.0 million. The Company finalized its allocation of purchase price in the fourth quarter of 2020, which did not result in a material change to the preliminary allocation.

Janrain

In January 2019, the Company acquired Janrain, Inc. ("Janrain"), a provider of customer identity and access management solutions, for $123.6 million in cash. The Company incorporated the Janrain technology into its Intelligent Edge Platform. The Company finalized its allocation of purchase price in the fourth quarter of 2019. The following table presents the final allocation of the purchase price for Janrain (in thousands):


Total purchase consideration	$	123,632

Allocation of the purchase consideration:
Cash	$	2,223
Accounts receivable	7,318
Prepaid expenses and other current assets	838
Identifiable intangible assets	26,930
Goodwill	92,188
Deferred tax asset	12,622
Other assets	87
Total assets acquired	142,206
Accounts payable	(1,642)
Accrued liabilities	(2,596)
Deferred revenue	(14,336)

Total liabilities assumed	(18,574)
Net assets acquired	$	123,632

The value of the goodwill can be attributed to a number of business factors, including a trained technical and sales workforce and cost synergies expected to be realized. The total amount of goodwill related to the acquisition of Janrain expected to be deductible for tax purposes is $45.7 million.

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	9,000	7.9
Customer-related intangible assets	17,700		13.9
Trademarks	200		1.9
Non-compete agreements	30		1.9
Total	$	26,930

The total weighted average amortization period for the intangible assets acquired from Janrain is 11.8 years. The intangible assets are being amortized based upon the pattern in which the economic benefits of the intangible assets are being utilized.

Commitments and Contingencies - Purchase Commitments (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Bandwidth Commitments
Unrecorded Unconditional Purchase Obligation [Line Items]
2021	$ 95,923
2022	19,046
2023	4,186
2024	120
2025	120
Thereafter	100
Total	119,495
Purchase Order Commitments
Unrecorded Unconditional Purchase Obligation [Line Items]
2021	231,059
2022	22,014
2023	9,640
2024	3,931
2025	0
Thereafter	0
Total	$ 266,644

Quarterly Financial Results (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 846,287	$ 792,845	$ 794,715	$ 764,302	$ 772,123	$ 709,912	$ 705,074	$ 706,508	$ 3,198,149	$ 2,893,617	$ 2,714,474
Cost of revenue (exclusive of amortization of acquired intangible assets shown below)	303,847	283,439	276,804	268,582	257,750	246,938	242,193	240,743	1,132,672	987,624	953,485
Net income	$ 113,370	$ 158,623	$ 161,915	$ 123,146	$ 119,100	$ 137,890	$ 113,915	$ 107,130	$ 557,054	$ 478,035	$ 298,373
Basic net income per share (in dollars per share)	$ 0.70	$ 0.97	$ 1.00	$ 0.76	$ 0.74	$ 0.85	$ 0.70	$ 0.66	$ 3.43	$ 2.94	$ 1.78
Diluted net income per share (in dollars per share)	$ 0.68	$ 0.95	$ 0.98	$ 0.75	$ 0.73	$ 0.84	$ 0.69	$ 0.65	$ 3.37	$ 2.90	$ 1.76

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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Revenue from Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The following table summarizes revenue by geography included in the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
U.S.	$	1,777,435	$	1,694,211	$	1,683,272
International	1,420,714		1,199,406		1,031,202
Total revenue	$	3,198,149	$	2,893,617	$	2,714,474

The following table summarizes revenue by division included in the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Web Division	$	1,666,305	$	1,556,252	$	1,439,772
Media and Carrier Division	1,531,844		1,337,365		1,274,702
Total revenue	$	3,198,149	$	2,893,617	$	2,714,474

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($) division	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) division	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Revenue	$ 846,287	$ 792,845	$ 794,715	$ 764,302	$ 772,123	$ 709,912	$ 705,074	$ 706,508	$ 3,198,149	$ 2,893,617	$ 2,714,474
Number of divisions \| division	2								2
Web Division
Disaggregation of Revenue [Line Items]
Revenue									$ 1,666,305	1,556,252	1,439,772
Media and Carrier Division
Disaggregation of Revenue [Line Items]
Revenue									1,531,844	1,337,365	1,274,702
U.S.
Disaggregation of Revenue [Line Items]
Revenue									1,777,435	1,694,211	1,683,272
International
Disaggregation of Revenue [Line Items]
Revenue									$ 1,420,714	$ 1,199,406	$ 1,031,202

- Definition

+ References

+ Details

Stock-Based Compensation - Schedule of Deferred Stock Units Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Deferred Stock Units
Units
Outstanding (in shares) \| shares	99
Granted (in shares) \| shares	24
Vested and distributed (in shares) \| shares	(9)
Outstanding (in shares) \| shares	114
Weighted Average Grant Date Fair Value
Outstanding (in dollars per share) \| $ / shares	$ 57.50
Granted (in dollars per share) \| $ / shares	100.58
Vested and distributed (in dollars per share) \| $ / shares	76.62
Outstanding (in dollars per share) \| $ / shares	$ 65.09
Restricted Stock Units (RSUs)
Units
Outstanding (in shares) \| shares	5,073
Granted (in shares) \| shares	2,710
Vested and distributed (in shares) \| shares	(2,881)
Forfeited (in shares) \| shares	(346)
Outstanding (in shares) \| shares	4,556
Weighted Average Grant Date Fair Value
Outstanding (in dollars per share) \| $ / shares	$ 70.43
Granted (in dollars per share) \| $ / shares	92.42
Vested and distributed (in dollars per share) \| $ / shares	69.04
Forfeited (in dollars per share) \| $ / shares	75.55
Outstanding (in dollars per share) \| $ / shares	$ 83.96

Fair Value Measurements

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurements

The following is a summary of available-for-sale marketable securities held as of December 31, 2020 and 2019 (in thousands):


			Gross Unrealized				Aggregate Fair Value		Classification on Balance Sheet
	Amortized Cost								Short-Term Marketable Securities		Long-Term Marketable Securities
As of December 31, 2020			Gains		Losses

Commercial paper	$	46,931	$	13	$	(8)	$	46,936	$	46,936	$	—
Corporate bonds	1,628,462		9,482		(262)		1,637,682		607,403		1,030,279
Municipal securities	3,495		—		(6)		3,489		—		3,489
U.S. government agency obligations	435,653		329		(63)		435,919		89,951		345,968
	$	2,114,541	$	9,824	$	(339)	$	2,124,026	$	744,290	$	1,379,736

As of December 31, 2019
Certificates of deposit	$	150,000	$	—	$	—	$	150,000	$	150,000	$	—
Commercial paper	73,829		23		(7)		73,845		73,845		—
Corporate bonds	1,368,668		1,840		(378)		1,370,130		753,538		616,592

U.S. government agency obligations	369,475		80		(74)		369,481		165,623		203,858
	$	1,961,972	$	1,943	$	(459)	$	1,963,456	$	1,143,006	$	820,450

The Company offers certain eligible employees the ability to participate in a non-qualified deferred compensation plan. The mutual funds held by the Company that are associated with this plan are classified as restricted trading securities. These securities are not included in the available-for-sale securities table above but are included in marketable securities in the consolidated balance sheets.

Unrealized gains and unrealized temporary losses on investments classified as available-for-sale are included within accumulated other comprehensive loss in the consolidated balance sheets. Upon realization, those amounts are reclassified from accumulated other comprehensive income to interest income in the consolidated statements of income. As of December 31, 2020, the Company held for investment corporate bonds with a fair value of $2.0 million, which are classified as available-for-sale marketable securities and have been in a continuous unrealized loss position for more than 12 months. The unrealized losses related to these corporate bonds were insignificant and are included in accumulated other comprehensive income as of December 31, 2020. The unrealized losses are attributable to changes in interest rates. Based on the evaluation of available evidence, the Company does not believe any unrealized losses represent other than temporary impairments.

The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets and liabilities as of December 31, 2020 and 2019 (in thousands):


	Total Fair Value		Fair Value Measurements at Reporting Date Using
			Level 1		Level 2		Level 3
As of December 31, 2020
Cash Equivalents and Marketable Securities:
Money market funds	$	74,417	$	74,417	$	—	$	—

Commercial paper	75,785		—		75,785		—
Corporate bonds	1,637,682		—		1,637,682		—
Municipal securities	3,489		—		3,489		—
U.S. government agency obligations	435,919		—		435,919		—
Mutual funds	19,932		19,932		—		—
	$	2,247,224	$	94,349	$	2,152,875	$	—

As of December 31, 2019
Cash Equivalents and Marketable Securities:
Money market funds	$	50,779	$	50,779	$	—	$	—
Certificates of deposit	150,000		—		150,000		—
Commercial paper	73,845		—		73,845		—
Corporate bonds	1,370,130		—		1,370,130		—

U.S. government agency obligations	369,481		—		369,481		—
Mutual funds	15,177		15,177		—		—
	$	2,029,412	$	65,956	$	1,963,456	$	—

As of December 31, 2020 and 2019, the Company grouped money market and mutual funds using a Level 1 valuation because market prices for such investments are readily available in active markets. As of December 31, 2020 and 2019, the Company grouped commercial paper, U.S. government agency obligations, corporate bonds and municipal securities using a Level 2 valuation because quoted prices for similar assets in active markets (or identical assets in an inactive market) are available. As of December 31, 2019, the Company also included bank certificates of deposit using Level 2 valuation because quoted prices for similar assets in active markets (or identical assets in an inactive market) are available. The Company did not have any transfers of assets or liabilities between Level 1 and Level 2 of the fair value measurement hierarchy during the years ended December 31, 2020 and 2019.

When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure fair value. The valuation technique used to measure fair value for the Company's Level 1 and Level 2 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are not available, the Company is required to make judgments about the assumptions market participants would use to estimate the fair value of a financial instrument.

The valuation technique used to measure the fair value of the Company's Level 3 liability, which consists of contingent consideration related to the acquisition of Cyberfend, Inc. in 2016, and which was paid upon achievement of milestones in 2019, was primarily an income-based approach. The significant unobservable input used in the fair value measurement of the contingent consideration is the likelihood of achieving development milestones to integrate the acquired technology into the Company's technology as well as achieving certain post-closing financial results.

Contractual maturities of the Company’s available-for-sale marketable securities held as of December 31, 2020 and 2019 were as follows (in thousands):


	December 31, 2020		December 31, 2019
Due in 1 year or less	$	744,290	$	1,143,006
Due after 1 year through 5 years	1,379,736		820,450
	$	2,124,026	$	1,963,456

The following table reflects the activity for the Company’s major classes of liabilities measured at fair value using Level 3 inputs for the years ended December 31, 2020 and 2019 (in thousands):


	2020		2019
Liability:
Beginning balance	$	—	$	(6,300)

Cash paid upon achievement of milestone	—		6,300
Ending balance	$	—	$	—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Revenue from Contracts with Customers - Performance Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 69.9	$ 64.1
Remaining performance obligation	2,900.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized	69.9	$ 64.1
Remaining performance obligation	$ 2,900.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, percentage	70.00%
Remaining performance obligation, expected timing	12 months

Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease Cost (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 197,128	$ 159,913
Short-term lease cost	15,849	14,412
Variable lease cost	55,494	39,134
Sublease income	(22,064)	(5,119)
Total operating lease costs	246,407	208,340
Real Estate Arrangements
Lessee, Lease, Description [Line Items]
Operating lease cost	83,574	63,893
Short-term lease cost	229	111
Variable lease cost	21,235	15,610
Sublease income	(22,064)	(5,119)
Total operating lease costs	82,974	74,495
Co-location Arrangements
Lessee, Lease, Description [Line Items]
Operating lease cost	113,554	96,020
Short-term lease cost	15,620	14,301
Variable lease cost	34,259	23,524
Sublease income	0	0
Total operating lease costs	$ 163,433	$ 133,845

Debt

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Debt

Convertible Notes – Due 2027

In August 2019, the Company issued $1,150.0 million in par value of convertible senior notes due 2027 (the "2027 Notes"). The 2027 Notes are senior unsecured obligations of the Company, bear regular interest of 0.375%, payable semi-annually in arrears on March 1 and September 1 of each year, beginning on March 1, 2020, and mature on September 1, 2027, unless repurchased or converted in accordance with their terms prior to maturity.

At their option, holders may convert their 2027 Notes prior to the close of business on the business day immediately preceding May 1, 2027, only under the following circumstances:

•during any calendar quarter commencing after the calendar quarter ended December 31, 2019 (and only during such calendar quarter), if the last reported sale price of the Company's common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;

•during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of 2027 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; or

•upon the occurrence of specified corporate events.

On or after May 1, 2027, holders may convert all or any portion of their 2027 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date.

Upon conversion, the Company, at its election, may pay or deliver to holders cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock. The initial conversion rate is 8.6073 shares of the Company's common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $116.18 per share, subject to adjustments in certain events, and represents a potential conversion into 9.9 million shares.

In accounting for the issuance of the 2027 Notes, the Company separated the 2027 Notes into liability and equity components. The carrying cost of the liability component was calculated by measuring the fair value of a similar debt obligation that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2027 Notes. The difference between the principal amount of the 2027 Notes and the proceeds allocated to the liability component (“debt discount”) is amortized to interest expense using the effective interest method over the term of the 2027 Notes. The equity component is recorded in additional paid-in capital in the consolidated balance sheet and will not be remeasured as long as it continues to meet the conditions for equity classification.

In accounting for the transaction costs related to the issuance of the 2027 Notes, the Company allocated the total transaction costs incurred to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are being amortized to interest expense over the term of the 2027 Notes, and transaction costs attributable to the equity component are netted against the equity component of the 2027 Notes in stockholders’ equity.

The 2027 Notes consisted of the following components as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Liability component:
Principal	$	1,150,000	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(196,359)		(222,928)
Net carrying amount	$	953,641	$	927,072

Equity component:	$	220,529	$	220,529

The estimated fair value of the 2027 Notes at December 31, 2020 was $1,277.8 million. The fair value was determined based on the quoted price of the 2027 Notes in an inactive market on the last trading day of the reporting period and has been classified as Level 2 within the fair value hierarchy. Based on the closing price of the Company's common stock of $104.99 on December 31, 2020, the value of the 2027 Notes if converted to common stock was less than the principal amount of $1,150.0 million.

The Company used $100.0 million of the proceeds from the offering to repurchase shares of its common stock, concurrent with the issuance of the 2027 Notes. The repurchase was made in accordance with a share repurchase program previously approved by the board of directors. Additionally, $127.1 million of the proceeds was used for the net cost of convertible note hedge and warrant transactions. The net proceeds are intended to be used for working capital, share repurchases, potential acquisitions and strategic transactions, and other corporate purposes.

Note Hedge

To minimize the impact of potential dilution upon conversion of the 2027 Notes, the Company entered into convertible note hedge transactions with respect to its common stock in August 2019. The Company paid $312.2 million for the note hedge transactions. The note hedge transactions cover approximately 9.9 million shares of the Company’s common stock at a strike price that corresponds to the initial conversion price of the 2027 Notes, also subject to adjustment, and are exercisable upon conversion of the 2027 Notes. The note hedge transactions are intended to reduce dilution in the event of conversion of the 2027 Notes.

Warrants

Separately, in August 2019, the Company entered into warrant transactions, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, up to 9.9 million shares of the Company’s common stock at a strike price of approximately $178.74 per share. The Company received aggregate proceeds of $185.2 million from the sale of the warrants. The convertible note hedge and warrant transactions will generally have the effect of increasing the conversion price of the 2027 Notes to approximately $178.74 per share.

Convertible Notes – Due 2025

In May 2018, the Company issued $1,150.0 million in par value of convertible senior notes due 2025 (the "2025 Notes"). The 2025 Notes are senior unsecured obligations of the Company, bear regular interest of 0.125%, payable semi-annually on May 1 and November 1 of each year, and mature on May 1, 2025, unless repurchased or converted prior to maturity.

At their option, holders may convert their 2025 Notes prior to the close of business on the business day immediately preceding January 1, 2025, only under the following circumstances:

•during any calendar quarter commencing after the calendar quarter ended June 30, 2018 (and only during such calendar quarter), if the last reported sale price of the Company's common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;

•during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of 2025 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; or

•upon the occurrence of specified corporate events.

On or after January 1, 2025, holders may convert all or any portion of their 2025 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances.

Upon conversion, the Company, at its election, may pay or deliver to holders cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock. The initial conversion rate is 10.5150 shares of the Company's common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $95.10 per share, subject to adjustments in certain events, and represents a potential conversion into 12.1 million shares.

In accounting for the issuance of the 2025 Notes, the Company separated the 2025 Notes into liability and equity components. The carrying cost of the liability component was calculated by measuring the fair value of a similar debt obligation that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2025 Notes. The difference between the principal amount of the 2025 Notes and the proceeds allocated to the liability component (“debt discount”) is amortized to interest expense using the effective interest method over the term of the 2025 Notes. The equity component is recorded in additional paid-in capital in the consolidated balance sheet and will not be remeasured as long as it continues to meet the conditions for equity classification.

In accounting for the transaction costs related to the issuance of the 2025 Notes, the Company allocated the total transaction costs incurred to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are being amortized to interest expense over the term of the 2025 Notes, and transaction costs attributable to the equity component are netted against the equity component of the 2025 Notes in stockholders’ equity.

The 2025 Notes consist of the following components as of December 31, 2020 and December 31, 2019 (in thousands):


	December 31, 2020		December 31, 2019
Liability component:
Principal	$	1,150,000	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(196,934)		(237,281)
Net carrying amount	$	953,066	$	912,719

Equity component:	$	285,225	$	285,225

The estimated fair value of the 2025 Notes at December 31, 2020 was $1,422.8 million. The fair value was determined based on the quoted price of the 2025 Notes in an inactive market on the last trading day of the reporting period and has been classified as Level 2 within the fair value hierarchy. Based on the closing price of the Company's common stock of $104.99 on December 31, 2020, the value of the 2025 Notes if converted to common stock was more than the principal amount of $1,150.0 million.

The Company used $46.2 million of the proceeds from the offering to repurchase shares of its common stock, concurrent with the issuance of the 2025 Notes. The repurchase was made in accordance with a share repurchase program previously approved by the board of directors. Additionally, $141.8 million of the proceeds was used for the net cost of convertible note hedge and warrant transactions. The Company also used a portion of the net proceeds to repay at maturity the $690.0 million in par value of convertible senior notes due in 2019.

Note Hedge

To minimize the impact of potential dilution upon conversion of the 2025 Notes, the Company entered into convertible note hedge transactions with respect to its common stock in May 2018. The Company paid $261.7 million for the note hedge transactions. The note hedge transactions cover approximately 12.1 million shares of the Company’s common stock at a strike price that corresponds to the initial conversion price of the 2025 Notes, also subject to adjustment, and are exercisable upon conversion of the 2025 Notes. The note hedge transactions are intended to reduce dilution in the event of conversion of the 2025 Notes.

Warrants

Separately, in May 2018, the Company entered into warrant transactions, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, up to 12.1 million shares of the Company’s common stock at a strike price of approximately $149.18 per share. The Company received aggregate proceeds of $119.9 million from the sale of the warrants. The convertible note hedge and warrant transactions will generally have the effect of increasing the conversion price of the 2025 Notes to approximately $149.18 per share.

Convertible Notes – Due 2019

In February 2014, the Company issued $690.0 million in par value of convertible senior notes due 2019 (the "2019 Notes"). The 2019 Notes were senior unsecured obligations of the Company and did not bear regular interest. The 2019 Notes matured and were repaid in full on February 15, 2019 as no repurchases or conversions occurred prior to maturity.

Revolving Credit Facility

In May 2018, the Company entered into a $500.0 million five-year, revolving credit agreement (the “Credit Agreement”). Borrowings under the Credit Agreement may be used to finance working capital needs and for general corporate purposes. The Credit Agreement provides for an initial $500.0 million in revolving loans. Under specified circumstances, the facility can be increased to up to $1.0 billion in aggregate principal amount. The Credit Agreement expires in May 2023.

Borrowings under the Credit Agreement bear interest, at the Company's option, at a base rate plus a spread of 0.00% to 0.25% or an adjusted LIBOR rate plus a spread of 0.875% to 1.25%, in each case with such spread being determined based on the Company's consolidated leverage ratio specified in the Credit Agreement. Regardless of what amounts, if any, are outstanding under the Credit Agreement, the Company is also obligated to pay an ongoing commitment fee on undrawn amounts at a rate of 0.075% to 0.15%, with such rate being based on the Company's consolidated leverage ratio specified in the Credit Agreement.

The Credit Agreement contains customary representations and warranties, affirmative and negative covenants and events of default. Principal covenants include a maximum consolidated leverage ratio and a minimum consolidated interest coverage ratio. There were no outstanding borrowings under the Credit Agreement as of December 31, 2020.

Interest Expense

The 2027 Notes bear interest at a fixed rate of 0.375%. The interest is payable semi-annually on March 1 and September 1 of each year, commencing in March 2020. The 2027 Notes have an effective interest rate of 3.1% attributable to the conversion feature. The 2025 Notes bear interest at a fixed rate of 0.125%. The interest is payable semi-annually on May 1 and November 1 of each year, commencing in November 2018. The 2025 Notes have an effective interest rate of 4.26% attributable to the conversion feature. The 2019 Notes did not bear regular interest, but had an effective interest rate of 3.2% attributable to the conversion feature. The Company is also obligated to pay ongoing commitment fees under the terms of the Credit Agreement. The following table sets forth total interest expense included in the consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Amortization of debt discount and issuance costs	$	67,153	$	52,059	$	46,493
Coupon interest payable on 2025 Notes	1,437		1,436		874
Coupon interest payable on 2027 Notes	4,312		1,557		—
Revolving credit facility contractual interest expense	548		513		368
Capitalization of interest expense	(4,330)		(6,201)		(4,533)
Total interest expense	$	69,120	$	49,364	$	43,202

Stock-Based Compensation - Schedule of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 197,411	$ 187,140	$ 183,813
Provision for income taxes	(62,153)	(51,177)	(48,502)
Total stock-based compensation, net of taxes	135,258	135,963	135,311
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	24,829	22,479	21,892
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	48,855	49,685	44,034
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	65,257	62,150	64,373
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 58,470	$ 52,826	$ 53,514

Accounts Receivable

12 Months Ended

Dec. 31, 2020

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

Accounts Receivable

Net accounts receivable consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Trade accounts receivable	$	473,474	$	396,204
Unbilled accounts receivable	188,400		157,619
Gross accounts receivable	661,874		553,823
Allowance for current expected credit losses and other reserves	(1,822)		(1,880)
Accounts receivable, net	$	660,052	$	551,943

A summary of activity in the accounts receivable allowance for current expected credit losses and other reserves for the years ended December 31, 2020, 2019 and 2018 is as follows (in thousands):


	2020		2019		2018
Beginning balance	$	1,880	$	1,534	$	1,281
Charges to income from operations	12,347		5,116		3,824
Collections from customers previously reserved and other	(12,405)		(4,770)		(3,571)
Ending balance	$	1,822	$	1,880	$	1,534

Charges to income from operations primarily represents charges to bad debt expense for increases in the allowance for current expected credit losses.

Debt - Schedule of Convertible Senior Notes (Details) - Convertible Debt - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Aug. 31, 2019	May 31, 2018	Feb. 28, 2014
2027 Notes
Liability component:
Principal	$ 1,150,000,000	$ 1,150,000,000	$ 1,150,000,000.0
Less: debt discount and issuance costs, net of amortization	(196,359,000)	(222,928,000)
Net carrying amount	953,641,000	927,072,000
Equity component:	220,529,000	220,529,000
2025 Notes
Liability component:
Principal	1,150,000,000	1,150,000,000		$ 1,150,000,000.0
Less: debt discount and issuance costs, net of amortization	(196,934,000)	(237,281,000)
Net carrying amount	953,066,000	912,719,000
Equity component:	$ 285,225,000	$ 285,225,000
2019 Notes
Liability component:
Principal					$ 690,000,000.0

Summary of Significant Accounting Policies - Concentration Risk (Details)	12 Months Ended
	Dec. 31, 2020
Concentration Risk [Line Items]
Expected life of customer arrangement	2 years 6 months
Customer Concentration Risk \| Sales
Concentration Risk [Line Items]
Concentration risk percent (more than)	10.00%
Customer Concentration Risk \| Accounts Receivable
Concentration Risk [Line Items]
Concentration risk percent (more than)	10.00%

Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Acquired Intangible Assets

Acquired intangible assets that are subject to amortization consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020						December 31, 2019
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Completed technologies	$	172,346	$	(111,435)	$	60,911	$	153,722	$	(94,088)	$	59,634
Customer-related intangible assets	358,032		(186,733)		171,299		279,684		(163,155)		116,529
Non-compete agreements	373		(77)		296		830		(529)		301
Trademarks and trade names	7,658		(5,440)		2,218		7,600		(4,633)		2,967
Acquired license rights	490		(490)		—		490		(490)		—
Total	$	538,899	$	(304,175)	$	234,724	$	442,326	$	(262,895)	$	179,431

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	17,300	10.1
Customer-related intangible assets	40,400		11.1
Trademarks	100		0.9
Non-compete agreements	270		2.9
Total	$	58,070

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	9,000	7.9
Customer-related intangible assets	17,700		13.9
Trademarks	200		1.9
Non-compete agreements	30		1.9
Total	$	26,930

Schedule of the Changes in the Carrying Amount of Goodwill

The changes in the carrying amount of goodwill for the years ended December 31, 2020 and 2019 were as follows (in thousands):


	2020		2019
Beginning balance	$	1,600,265	$	1,487,404
Acquisition of Asavie Technologies Limited	70,200		—
Acquisition of Janrain, Inc.	—		92,188
Acquisition of Exceda	—		14,712
Acquisition of ChameleonX, Ltd.	—		7,069
Measurement period adjustments related to acquisitions completed in prior years	(1,056)		—
Foreign currency translation	4,962		(1,108)
Ending balance	$	1,674,371	$	1,600,265

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 27,359	$ 64,892	$ 85,845
Gross increases – tax positions of prior periods	2,539	74	2,704
Gross increases – current period tax positions	1,946	2,006	3,021
Gross decreases – tax positions of prior periods	(3,540)	(5,201)	(15,287)
Gross decreases – lapse of applicable statute of limitations	(4,199)	(28,672)	(6,186)
Gross decreases – settlements	0	(5,740)	(5,205)
Balance at end of year	$ 24,105	$ 27,359	$ 64,892

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The Company prepares its consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. These principles require management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, and the amounts disclosed in the related notes to the consolidated financial statements. Actual results and outcomes may differ materially from management’s estimates, judgments and assumptions. Significant estimates, judgments and assumptions used in these financial statements include, but are not limited to, those related to revenue, accounts receivable and related reserves, valuation and impairment of investments and marketable securities, valuation and useful lives of acquired intangible assets, useful lives and realizability of long-lived assets, capitalized internal-use software development costs, income tax reserves and accounting for stock-based compensation. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. The effects of material revisions in estimates are reflected in the consolidated financial statements prospectively from the date of the change in estimate.
Newly-Adopted Accounting Pronouncements and Recent Accounting Pronouncements	Newly-Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board ("FASB") issued guidance that introduces a new methodology for accounting for credit losses on financial instruments. The guidance establishes a new "expected credit loss model" that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Any expected credit losses are to be reflected as allowances. The Company prospectively adopted this standard on January 1, 2020. Adoption of the standard did not have a material impact on the Company's consolidated financial statements. In August 2018, the FASB issued guidance that addresses a customer’s accounting for implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance aligns the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement with the guidance for capitalizing costs associated with developing or obtaining internal-use software. The Company prospectively adopted this standard on January 1, 2020. Adoption of the standard did not have a material impact on the Company's consolidated financial statements. Recent Accounting Pronouncements In August 2020, the FASB issued guidance that is expected to reduce complexity and improve comparability of financial reporting associated with accounting for convertible instruments and contracts in an entity’s own equity. This guidance will be effective for the Company on January 1, 2022. The Company is evaluating the potential impact of adopting this new accounting guidance on its consolidated financial statements related to the accounting for convertible debt arrangements.
Cash, Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash held in bank deposit accounts and short-term, highly-liquid investments with remaining maturities of three months or less at the date of purchase. Marketable securities consist of corporate, government and other securities. Securities having remaining maturities of less than one year from the date of the balance sheet are classified as short-term, and those with maturities of more than one year from the date of the balance sheet are classified as long-term in the consolidated balance sheets. The Company classifies its debt securities with readily determinable market values as available-for-sale. These investments are classified as marketable securities on the consolidated balance sheets and are carried at fair market value, with unrealized gains and losses considered to be temporary in nature and reported as accumulated other comprehensive loss, a separate component of stockholders’ equity. The Company reviews all investments for reductions in fair value that are other-than-temporary. When such reductions occur, the cost of the investment is adjusted to fair value through recording a loss on investments in the consolidated statements of income. Gains and losses on investments are calculated on the basis of specific identification. Marketable securities are considered to be impaired when a decline in fair value below cost basis is determined to be other-than-temporary. The Company periodically evaluates whether a decline in fair value below cost basis is other-than-temporary by considering available evidence regarding these investments including, among other factors: the duration of the period that, and extent to which, the fair value is less than cost basis; the financial health and business outlook of the issuer, including industry and sector performance and operational and financing cash flow factors; overall market conditions and trends; and the Company’s intent and ability to retain its investment in the security for a period of time sufficient to allow for an anticipated recovery in market value. Once a decline in fair value is determined to be other-than-temporary, a write-down is recorded and a new cost basis in the security is established. Assessing the above factors involves inherent uncertainty. Write-downs, if recorded, could be materially different from the actual market performance of marketable securities in the Company’s portfolio if, among other things, relevant information related to the marketable securities was not publicly available or other factors not considered by the Company would have been relevant to the determination of impairment.
Accounts Receivable and Related Reserves	Accounts Receivable and Related Reserves The Company’s accounts receivable balance includes unbilled amounts that represent revenue recorded for customers that are typically billed monthly in arrears. The Company records reserves against its accounts receivable balance which primarily consists of allowances for current expected credit losses. Increases and decreases in the allowance for current expected credit losses are included as a component of general and administrative expense in the consolidated statements of income. The allowance for current expected credit losses has been developed using historical loss rates for the previous twelve months as well as expectations about the future where the Company has been able to develop forecasts to support its estimates. In addition, the allowance considers outstanding balances on a customer-specific, account-by-account basis. The Company assesses collectibility based upon a review of customer receivables from prior sales with collection issues where the Company no longer believes that the customer has the ability to pay for services previously provided. The Company also performs ongoing credit evaluations of its customers. If such an evaluation indicates that payment is no longer reasonably assured for services provided, any future services provided to that customer will result in the creation of a cash-basis reserve until the Company receives consistent payments. The Company does not have any off-balance sheet credit exposure related to its customers.
Revenue Recognition, Incremental Costs to Obtain a Contract with a Customer, Contract Liabilities and Cost of Revenue	Incremental Costs to Obtain a Contract with a Customer The Company capitalizes incremental costs associated with obtaining customer contracts, specifically certain commission and incentive payments. The Company pays commissions and incentives up-front based on contract value upon signing a new arrangement with a customer and upon renewal and upgrades of existing contracts with customers if the renewal and upgrades result in an incremental increase in contract value. To the extent commissions and incentives are earned, the expenses, including estimated payroll taxes, are deferred on the Company's consolidated balance sheet and amortized over the expected life of the customer arrangement on a straight-line basis. Based on the nature of the Company's unique technology and services, and the rate at which the Company continually enhances and updates its technology, the expected life of the customer arrangement is determined to be approximately 2.5 years. Additionally, the Company may pay commissions and incentives based upon contract value, rather than incremental increase in contract value, to certain sales groups within the Company. For these commission arrangements, the Company amortizes capitalized costs for contract renewals over an average renewal contract period of 16 months. The Company also incurs commission expense on an ongoing basis based upon revenue recognized. In these cases, no incremental costs are deferred, as the commissions are earned and expensed in the same period for which the associated revenue is recognized. Amortization of the costs is primarily included in sales and marketing expense in the consolidated statements of income. The current portion of deferred commission and incentive payments is included in prepaid expenses and other current assets, and the long-term portion is included in other assets on the Company's consolidated balance sheets. Contract Liabilities Contract liabilities primarily represent payments received from customers for which the related performance obligations have not yet been satisfied. These balances consist of the unearned portion of monthly service fees and integration fees and prepayments made by customers for future periods. The current and long-term portions of the Company's contract liabilities are included in deferred revenue in the respective sections of the Company's consolidated balance sheets. Revenue Recognition The Company primarily derives revenue from the sale of services to customers executing contracts having terms of one year or longer. Services included in the Company's contracts consist of its core services – the delivery of content, applications and software over the internet – as well as security solutions and professional services. Revenue is recognized upon transfer of control of promised services in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company enters into contracts that may include various combinations of these services, which are generally capable of being distinct and accounted for as separate performance obligations. These contracts generally commit the customer to a minimum of monthly, quarterly or annual levels of usage and specify the rate at which the customer must pay for actual usage above the stated minimum. Based on the typical structure of the Company's contracts, which are generally for monthly recurring services that are essentially the same over time and have the same pattern of transfer to the customer, most performance obligations represent a promise to deliver a series of distinct services over time. The Company's contracts with customers sometimes include promises to deliver multiple services to a customer. Determining whether services are distinct performance obligations often requires the exercise of judgment by management. For example, advanced features that enhance a service and are highly interrelated are generally not considered distinct; rather, they are combined with the service they relate to into one performance obligation. Different determinations related to combining services into performance obligations could result in differences in the timing and amount of revenue recognized in a period. Generally, the transaction price in a contract is equal to the committed price stated in the contract, less any discounts or rebates. The Company's typical contracts qualify for series accounting, and the pricing terms generally do not require estimation of the transaction price beyond the reporting period. As a result, any incremental fees generated as a result of usage or “bursting” over committed contract levels are recorded in the period to which the services relate. The amount of consideration recognized for usage above contract minimums is limited to the amount the Company expects to be entitled to receive in exchange for providing the services. Once the transaction price has been determined, the Company allocates such price among all performance obligations in the contract on a relative standalone selling price (“SSP”) basis. Determination of SSP requires the exercise of judgment by management. SSP is based on observable inputs such as the price the Company charges for the service when sold separately or the discounted list price per management’s approved price list. In cases where services are not sold separately or price list rates are not available, a cost-plus-margin approach or adjusted market approach is used to determine SSP. Most content delivery and security services represent stand-ready obligations that are satisfied over time as the customer simultaneously receives and consumes the benefits provided by the Company. Accordingly, revenue for those services is recognized over time, generally ratably over the term of the arrangement due to consistent monthly traffic commitments that expire each period. Any bursting over given commitments is recognized in the period in which the traffic was served. For services that involve traffic consumption, revenue is recognized in an amount that reflects the level of traffic served to a customer in a given period. For custom arrangements, other methods may be used as a measure of progress towards satisfying the performance obligations. Some of the Company's services are satisfied at a point in time, such as one-time professional services contracts, integration services and most license sales where the primary obligation is delivery of the license at the start of the term. In these cases, revenue is recognized at the point in time of delivery or satisfaction of the performance obligation. From time to time, the Company enters into contracts to sell its services or license its technology to unrelated enterprises at or about the same time that it enters into contracts to purchase products or services from the same enterprises. Consideration payable to a customer is reviewed as part of the transaction price. If the payment to the customer does not represent payment for a distinct service, revenue is recognized only up to the net amount of consideration after customer payment obligations are considered. The Company may also resell the licenses or services of third parties. If the Company is acting as an agent in an arrangement with a customer to provide third party services, the transaction price reflects only the net amount to which the Company will be entitled, after accounting for payments made to the third party responsible for satisfying the performance obligation. Cost of Revenue Cost of revenue consists primarily of fees paid to network providers for bandwidth and to third-party network data centers for housing servers, also known as co-location costs. Cost of revenue also includes employee costs for services delivery and network operation, build-out and support of the Company's network; network storage costs; cost of software licenses; depreciation of network equipment used to deliver the Company’s services; amortization of network-related internal-use software; and costs for the production of live events streamed by the Company for customers. The Company enters into contracts for bandwidth with third-party network providers with terms typically ranging from several months to five years. These contracts generally commit the Company to pay minimum monthly fees plus additional fees for bandwidth usage above the committed level. In some circumstances, internet service providers (“ISPs”) make rack space available for the Company to locate its servers and provide access to their bandwidth at a discount or no cost. Although the Company does not provide any goods or services to the ISPs or the ISPs’ customers under these arrangements, the ISPs and their customers indirectly benefit by accessing content through a local Company server, resulting in better content delivery. The Company records the cost of these vendor relationships at their negotiated transaction price, which is either at a discount or no cost.
Concentrations of Credit Risk	Concentrations of Credit Risk The amounts reflected in the consolidated balance sheets for accounts receivable, other current assets, accounts payable, accrued liabilities and other current liabilities approximate fair values due to their short-term maturities. The Company maintains the majority of its cash, cash equivalents and marketable securities with major financial institutions that the Company believes to be of high credit standing. The Company believes that, as of December 31, 2020, its concentration of credit risk related to cash equivalents and marketable securities was not significant. Concentrations of credit risk with respect to accounts receivable are primarily limited to certain customers to which the Company makes substantial sales. The Company’s customer base consists of a large number of geographically-dispersed customers diversified across several industries. To reduce risk, the Company routinely assesses the financial strength of its customers. Based on such assessments, the Company believes that its accounts receivable credit risk exposure is limited. For the years ended December 31, 2020, 2019 and 2018, no customer accounted for more than 10% of total revenue. As of December 31, 2020 and 2019, no customer had an accounts receivable balance greater than 10% of total accounts receivable. The Company believes that, as of December 31, 2020, its concentration of credit risk related to accounts receivable was not significant.
Fair Value of Financial Measurements	Fair Value of Financial Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company has certain financial assets and liabilities recorded at fair value, principally cash equivalents and short- and long-term marketable securities that have been classified as Level 1, 2 or 3 within the fair value hierarchy. Fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company can access at the reporting date. Fair values determined by Level 2 inputs utilize data points other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Fair values determined by Level 3 inputs are based on unobservable data points for the asset or liability.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Property and equipment generally include purchases of items with a per-unit value greater than $1,000 and an estimated useful life greater than one year. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the related lease terms or their estimated useful lives. The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in income from operations. Repairs and maintenance costs are expensed as incurred.
Operating Leases	Operating Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued guidance that requires companies to present assets and liabilities arising from leases on the consolidated balance sheet. The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize right of use ("ROU") assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The Company adopted this standard on January 1, 2019 on a modified retrospective basis by applying the new standard to its lease portfolio as of January 1, 2019, while continuing to apply legacy guidance in the comparative periods. The Company enters into operating leases for real estate assets related to office space and co-location assets related to space or racks at co-location facilities and related equipment for its servers and other networking equipment. The Company determines if an arrangement contains a lease at the inception of a contract by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration and the right to obtain the economic benefits from the use of the identified asset. Upon commencement of a lease, the Company records a right-of-use asset that represents the Company’s right to use the underlying asset for the lease term and a lease liability that represents an obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. Lease payments are discounted at the lease commencement date. As the Company’s leases do not provide an implicit rate, an incremental borrowing rate has been applied based on the Company's credit-adjusted risk-free rate. The Company often enters into contracts that contain both lease and non-lease components. Real estate non-lease components include real estate taxes, insurance, maintenance, parking and other operating costs. Co-location non-lease components include utilities and other operating costs. The Company includes both lease and non-lease components of fixed costs in its lease arrangements as a single lease component. Variable costs, such as utilities based on actual usage, are not included in the measurement of right-of-use assets and lease liabilities but are expensed when the event determining the amount of variable consideration to be paid occurs. The Company’s lease terms often include renewal options and, particularly in the case of co-location arrangements, may include evergreen provisions. The Company’s right-of-use assets and lease liabilities generally do not include the options to extend, or terminate, unless it is reasonably certain that the Company will exercise these options. The Company has elected to exclude leases for certain networking equipment with terms of 12 months or less from its right-of-use assets and lease liabilities on its consolidated balance sheet. Lease expense is recognized on a straight-line basis over the expected lease term.
Equity Method Investments	Equity Method Investments The Company accounts for equity investments in which it has significant influence, but not a controlling financial interest, using the equity method of accounting. Under the equity method of accounting, investments are initially recorded at cost, less impairment, and subsequently adjusted to recognize the Company’s share of earnings or losses.
Goodwill, Acquired Intangible Assets and Long-Lived Assets	Goodwill, Acquired Intangible Assets and Long-Lived Assets Goodwill is the amount by which the cost of acquired net assets in a business combination exceeds the fair value of the net identifiable assets on the date of purchase and is carried at its historical cost. The Company tests goodwill for impairment on an annual basis or more frequently if events or changes in circumstances indicate that the asset might be impaired. The Company performs its impairment test of goodwill as of December 31 each year. As of December 31, 2020, 2019 and 2018, the fair value of the Company's reporting unit was substantially in excess of the carrying value. The tests did not result in an impairment to goodwill during the years ended December 31, 2020, 2019 and 2018. Acquired intangible assets consist of completed technologies, customer relationships, trademarks and trade names, non-compete agreements and acquired license rights. Acquired intangible assets, other than goodwill, are amortized over their estimated useful lives based upon the estimated economic value derived from the related intangible asset. Long-lived assets, including property and equipment and acquired intangible assets, are reviewed for impairment whenever events or changes in circumstances, such as service discontinuance, technological obsolescence, significant decreases in the Company’s market capitalization, facility closures or work-force reductions indicate that the carrying amount of the long-lived asset may not be recoverable. When such events occur, the Company compares the carrying amount of the asset to the undiscounted expected future cash flows related to the asset. If this comparison indicates that an impairment is present, the amount of the impairment is calculated as the difference between the carrying amount and the fair value of the asset.
Research and Development Costs and Capitalized Internal-Use Software	Research and Development Costs and Capitalized Internal-Use Software Research and development costs consist primarily of payroll and related personnel costs for the design, development, deployment, testing and enhancement of the Company’s services and network. Costs incurred in the development of the Company’s services are expensed as incurred, except certain internal-use software development costs eligible for capitalization. Capitalized costs include external consulting fees, payroll and payroll-related costs and stock-based compensation for employees in the Company’s development and information technology groups who are directly associated with, and who devote time to, the Company’s internal-use software projects. Capitalization begins when the planning stage is complete and the Company commits resources to the software project; capitalization continues during the application development stage. Capitalization ceases when the software has been tested and is ready for its intended use. Costs incurred during the planning, training and post-implementation stages of the software development life-cycle are expensed as incurred. The Company amortizes completed internal-use software that is used on its network to cost of revenue over its estimated useful life.
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation The Company recognizes compensation costs for all stock-based payment awards made to employees based upon the awards’ grant-date fair value. The stock-based payment awards include stock options, restricted stock units, deferred stock units and employee stock purchases related to the Company’s employee stock purchase plan. For stock options, the Company has selected the Black-Scholes option-pricing model to determine the fair value of stock option awards. For stock awards with market-based vesting conditions, the Company uses a Monte Carlo simulation to determine the fair value of the award. For stock options, restricted stock units and deferred stock units that contain only a service-based vesting feature, the Company recognizes compensation cost on a straight-line basis over the award's vesting period. For awards with a performance condition-based vesting feature, the Company recognizes compensation cost on a graded-vesting basis over the award's expected vesting period, commencing when achievement of the performance condition is deemed probable. In addition, for awards that vest and become exercisable only upon achievement of specified performance conditions, the Company makes judgments and estimates each quarter about the probability that such performance conditions will be met or achieved. Any changes to those estimates that the Company makes from time to time may have a significant impact on the stock-based compensation expense recorded and could materially impact the Company’s results of operations.
Foreign Currency Translation and Forward Currency Contracts	Foreign Currency Translation and Forward Currency Contracts The assets and liabilities of the Company's subsidiaries are translated at the applicable exchange rate as of the balance sheet date, and revenue and expenses are translated at an average rate over the period. Resulting currency translation adjustments are recorded as a component of accumulated other comprehensive loss, a separate component of stockholders’ equity. Gains and losses on inter-company and other non-functional currency transactions are recorded in other expense, net. The Company enters into short-term foreign currency forward contracts to offset foreign exchange gains and losses generated by the re-measurement of certain assets and liabilities recorded in non-functional currencies. Changes in the fair value of these derivatives, as well as re-measurement gains and losses, are recognized in current earnings in other expense, net. As of December 31, 2020 and 2019, the fair value of the forward currency contracts and the underlying net gains for the years ended December 31, 2020, 2019 and 2018 were immaterial. The Company's foreign currency forward contracts may be exposed to credit risk to the extent that its counterparties are unable to meet the terms of the agreements. The Company seeks to minimize counterparty credit (or repayment) risk by entering into transactions only with major financial institutions of investment grade credit rating.
Income Taxes	Income Taxes The Company's provision for income taxes is comprised of a current and a deferred portion. The current income tax provision is calculated as the estimated taxes payable or refundable on tax returns for the current year. The deferred income tax provision is calculated as the estimated future tax effects attributable to temporary differences and carryforwards using expected tax rates in effect in the years during which the differences are expected to reverse or the carryforwards are expected to be realized. The Company currently has net deferred tax assets consisting of net operating loss (“NOL”) carryforwards, tax credit carryforwards and deductible temporary differences. Management periodically weighs the positive and negative evidence to determine if it is more-likely-than-not that some or all of the deferred tax assets will be realized. The Company has recorded certain tax reserves to address potential exposures involving its income tax positions. These potential tax liabilities result from the varying application of statutes, rules, regulations and interpretations by different taxing jurisdictions. The Company's estimate of the value of its tax reserves contains assumptions based on past experiences and judgments about the interpretation of statutes, rules and regulations by taxing jurisdictions. It is possible that the costs of the ultimate tax liability or benefit from these matters may be more or less than the amount the Company estimated. Uncertainty in income taxes is recognized in the Company's consolidated financial statements using a two-step process. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination. If the tax position is deemed more-likely-than-not to be sustained based on technical merit, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement.

Net Income per Share - Schedule of Anti-Dilutive Securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from computation	36,913	46,094	42,002
Service-based RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from computation	591	763	899
Market-and performance-based RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from computation	1,409	1,349	1,509
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from computation	12,922	21,991	19,797
Warrants related to issuance of convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from computation	21,991	21,991	19,797

Commitments and Contingencies - Narrative (Details) - Settled Litigation $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2016 USD ($) installment	Jun. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Patent Infringement Case Against Limelight
Gain and Loss Contingencies [Line Items]
Settlement amount	$ 54.0
Number of installments in settlement \| installment	12
Settlement payment term	3 years
Proceeds from settlements			$ 9.0	$ 18.0
Multiple Existing Lawsuits Between Limelight Networks, Inc. and the Company
Gain and Loss Contingencies [Line Items]
Settlement amount		$ 14.9

Income Taxes - Schedule of NOL Carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Federal and state research and development tax credit and other credit carryforwards	$ 132,800	$ 88,570
Domestic country
Operating Loss Carryforwards [Line Items]
NOL carryforwards:	59,200	87,500
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
NOL carryforwards:	24,800	20,500
Foreign country
Operating Loss Carryforwards [Line Items]
NOL carryforwards:	$ 40,800	$ 11,600

Income Taxes - Schedule of Deferred Tax and Related Valuation Allowance (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Accrued bonus	$ 25,480	$ 25,487
Deferred revenue	11,146	3,874
Operating lease liability	141,212	147,375
Stock-based compensation	23,629	20,606
NOLs	25,255	25,851
Unrealized losses	0	1,529
Tax credit carryforwards	110,254	87,305
Convertible senior notes interest	20,953	22,506
Other	11,531	12,501
Deferred tax assets	369,460	347,034
Depreciation and amortization	(6,974)	(16,896)
Acquired intangible assets	(59,128)	(51,758)
Operating lease right-of-use asset	(127,524)	(132,949)
Deferred commissions	(14,952)	(14,843)
Internal-use software development costs capitalized	(58,820)	(57,201)
Deferred tax liabilities	(267,398)	(273,647)
Valuation allowance	(32,602)	(26,046)
Net deferred tax assets	$ 69,460	$ 47,341

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Accounts Payable and Accrued Liabilities, Current [Abstract]

Schedule of Accrued Expenses

Accrued expenses consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Payroll and other related benefits	$	218,588	$	190,721
Bandwidth and co-location	67,170		65,213
Income tax payable	50,812		40,337
Property, use and other taxes	35,390		30,904
Professional service fees	2,245		1,775
Other accrued expenses	6,263		5,911
Total	$	380,468	$	334,861

Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2020	Feb. 23, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	0-27275
Entity Registrant Name	Akamai Technologies, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3432319
Entity Address, Address Line One	145 Broadway
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	617
Local Phone Number	444-3000
Title of 12(b) Security	Common Stock - par value $0.01 per share
Trading Symbol	AKAM
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 17,181.1
Entity Common Stock, Shares Outstanding		163,220,270
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement to be filed with the Securities and Exchange Commission relative to the registrant’s 2021 Annual Meeting of Stockholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this annual report on Form 10-K
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001086222

Akamai Foundation	12 Months Ended
Akamai Foundation	Dec. 31, 2020
Related Party Transactions [Abstract]
Akamai Foundation	Akamai FoundationThe Akamai Foundation is a private non-profit organization founded by certain current and former employees of the Company in 2000 (the “Foundation”). The Company has the right to appoint the directors of the Foundation, but receives no economic benefit from the Foundation’s initiatives, therefore the Foundation is not consolidated. The Foundation's initiatives are to support youth education, with a focus on mathematics and science, as well as other charitable causes. In 2020, the Foundation expanded its initiatives to include supporting increased diversity in the technology industry. In 2018, the Company contributed $50.0 million to establish a permanent endowment for the Foundation. In 2020, the Company contributed an additional $20.0 million in support of the Foundation's expanded initiatives. These expenses are included in general and administrative expenses in the consolidated statements of income in the years in which they were contributed.

Restructuring

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Restructuring

During the fourth quarter of 2020, management committed to an action to restructure certain parts of the Company to better position us to become more agile in delivering our solutions. As a result, certain headcount reductions were necessary and certain capitalized internal-use software charges were realized for software not yet placed into service that will not be completed and implemented due to this action. The Company incurred expenses of $23.6 million for the year ended December 31, 2020 and expects to incur up to $7.0 million in 2021 for severance and related benefits related to this action.

During the fourth quarter of 2019, management committed to an action to restructure certain parts of the Company to focus on investments with the potential to accelerate revenue growth. As a result, certain headcount reductions were necessary and certain capitalized internal-use software charges were realized for software not yet placed into service that will not be completed and implemented due to this action. The Company incurred expenses of $23.4 million related to this action, of which $13.2 million were incurred during the year ended December 31, 2020 and $10.2 million were incurred during the year ended December 31, 2019. Also included within the 2020 charge is $8.7 million for lease related assets that were incurred to exit the leased facilities. The Company does not expect any additional restructuring charges related to this action.

During the fourth quarter of 2018, management committed to an action to restructure certain parts of the Company with the intent of re-balancing investments to ensure long-term growth and scale. As a result, certain headcount reductions were necessary and certain capitalized internal-use software charges were realized for software not yet placed into service that will not be completed and implemented due to this action. The Company incurred expenses of $19.0 million related to this action, of which $6.7 million were incurred during the year ended December 31, 2019 and $12.3 million were incurred during the year ended December 31, 2018. The Company does not expect any additional restructuring charges related to this action.

The Company also recognizes restructuring charges for redundant employees, facilities and contracts associated with completed acquisitions. Restructuring charges related to acquisitions were not material in any of the years ended December 31, 2020, 2019 and 2018.

The following table summarizes the activity of the Company's restructuring accrual during the years ended December 31, 2020, 2019 and 2018 (in thousands):


	Employee Severance and Related Benefits		Software Charges		Other		Total
Balance January 1, 2018	$	12,857	$	—	$	1,386	$	14,243
Costs incurred	15,841		4,940		6,813		27,594
Cash disbursements	(18,922)		—		(5,932)		(24,854)
Software and other non-cash charges	—		(4,742)		(1,787)		(6,529)
Translation adjustments and other	732		—		(205)		527
Balance December 31, 2018	10,508		198		275		10,981
Costs incurred	12,455		3,784		914		17,153
Cash disbursements	(17,294)		(99)		(1,038)		(18,431)
Software and other non-cash charges	—		(3,784)		—		(3,784)
Translation adjustments and other	38		—		—		38
Balance December 31, 2019	5,707		99		151		5,957
Costs incurred	26,332		833		1,380		28,545
Cash disbursements	(10,118)		(99)		(1,531)		(11,748)
Software and other non-cash charges	—		(833)		—		(833)
Translation adjustments and other	130		—		—		130
Balance December 31, 2020	$	22,051	$	—	$	—	$	22,051

Debt - Revolving Credit Facility (Details) - Credit Agreement - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2020
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 500,000,000.0
Debt term	5 years
Maximum borrowing capacity under specific conditions	$ 1,000,000,000.0
Outstanding borrowings		$ 0
Minimum
Debt Instrument [Line Items]
Commitment fee		0.075%
Maximum
Debt Instrument [Line Items]
Commitment fee		0.15%
Base Rate \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.00%
Base Rate \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		0.25%
LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.875%
LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		1.25%

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Valuation allowance	$ 32,602	$ 26,046
Increase in valuation allowance	6,600
Foreign earnings repatriated	985,700
Unrecognized tax benefits including accrued interest and penalties	29,500	32,600	$ 67,800
Unrecognized tax benefits, income tax penalties and interest accrued	7,700	7,800	11,800
Income tax interest and penalties expense	1,200	$ 1,100	$ 1,300
Unrecognized tax benefits that, if recognized, would impact the effective income tax rate	29,500
Unrecognized tax benefits that may be recognized	9,600
Estimate of possible charge	41,000
Stat tax credits	$ 27,000

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable reserve	$ 1,822	$ 1,880
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares designated as Series A Junior Participating Preferred Stock	700,000	700,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	700,000,000	700,000,000
Common stock, shares issued	162,709,720	162,000,843
Common stock, shares outstanding	162,709,720	162,000,843

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 557,054	$ 478,035	$ 298,373
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	478,389	440,674	434,520
Stock-based compensation	197,411	187,140	183,813
(Benefit) provision for deferred income taxes	(33,821)	933	2,339
Amortization of debt discount and issuance costs	62,823	45,857	41,958
Other non-cash reconciling items, net	23,027	8,528	17,018
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(90,381)	(64,471)	(30,445)
Prepaid expenses and other current assets	(25,395)	11,689	(4,132)
Accounts payable and accrued expenses	39,211	8,769	42,238
Deferred revenue	(1,318)	(13,547)	(919)
Other current liabilities	18,101	(17,230)	9,422
Other non-current assets and liabilities	(10,101)	(28,073)	14,142
Net cash provided by operating activities	1,215,000	1,058,304	1,008,327
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	(127,999)	(165,329)	(79)
Cash paid for asset acquisition	(36,376)	0	0
Cash paid for equity method investment	0	(36,008)	0
Purchases of property and equipment	(514,313)	(359,667)	(217,609)
Capitalization of internal-use software development costs	(217,559)	(202,410)	(188,132)
Purchases of short-and long-term marketable securities	(1,782,849)	(1,990,148)	(873,697)
Proceeds from sales of short-and long-term marketable securities	30,350	856	16,569
Proceeds from maturities of short-and long-term marketable securities	1,597,651	1,084,373	758,481
Other non-current assets and liabilities	8,121	399	(2,066)
Net cash used in investing activities	(1,042,974)	(1,667,934)	(506,533)
Cash flows from financing activities:
Proceeds from the issuance of convertible senior notes	0	1,135,629	1,132,185
Proceeds from the issuance of warrants	0	185,150	119,945
Purchase of note hedge related to convertible senior notes	0	(312,225)	(261,740)
Repayment of convertible senior notes	0	(690,000)	0
Proceeds related to the issuance of common stock under stock plans	59,775	57,112	62,608
Employee taxes paid related to net share settlement of stock-based awards	(89,828)	(75,266)	(64,305)
Repurchases of common stock	(193,588)	(334,519)	(750,000)
Other non-current assets and liabilities	0	(1,558)	(5,085)
Net cash (used in) provided by financing activities	(223,641)	(35,677)	233,608
Effects of exchange rate changes on cash, cash equivalents and restricted cash	10,935	2,466	(12,844)
Net (decrease) increase in cash, cash equivalents and restricted cash	(40,680)	(642,841)	722,558
Cash, cash equivalents and restricted cash at beginning of year	394,146	1,036,987	314,429
Cash, cash equivalents and restricted cash at end of year	353,466	394,146	1,036,987
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds received in the years ended December 31, 2020, 2019 and 2018 of $17,491, $3,731 and $18,501, respectively	79,163	73,898	45,129
Cash paid for interest expense	5,954	1,438	639
Cash paid for operating lease liabilities	201,856	153,818
Non-cash activities:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	200,735	529,376
Purchases of property and equipment and capitalization of internal-use software development costs included in accounts payable and accrued expenses	75,666	88,238	54,867
Capitalization of stock-based compensation	$ 38,333	$ 35,905	$ 34,785

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consisted of the following as of December 31, 2020 and 2019 (in thousands except years):


	December 31, 2020		December 31, 2019		Estimated Useful Life (in years)
Computer and networking equipment	$	1,847,717	$	1,469,293	3-7
Purchased software	95,662		90,450		3-10
Furniture and fixtures	71,119		65,683		1-7
Office equipment	40,235		38,178		3-5
Leasehold improvements	230,423		235,279		1-15
Internal-use software	1,234,934		1,132,180		2-7
Property and equipment, gross	3,520,090		3,031,063
Accumulated depreciation and amortization	(2,041,818)		(1,878,910)
Property and equipment, net	$	1,478,272	$	1,152,153

Accumulated Other Comprehensive Loss

12 Months Ended

Dec. 31, 2020

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Accumulated Other Comprehensive Loss


	Foreign Currency Translation		Net Unrealized Gains on Investments		Total
Balance as of January 1, 2019	$	(51,904)	$	2,992	$	(48,912)
Other comprehensive (loss) income	(1,020)		4,788		3,768
Balance as of December 31, 2019	(52,924)		7,780		(45,144)
Other comprehensive income	19,629		5,314		24,943
Balance as of December 31, 2020	$	(33,295)	$	13,094	$	(20,201)

Amounts reclassified from accumulated other comprehensive loss to net income were insignificant for the years ended December 31, 2020 and 2019.

Quarterly Financial Results (unaudited)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Results (unaudited)


(in thousands, except per share data)	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Year ended December 31, 2020:
Revenue	$	764,302	$	794,715	$	792,845	$	846,287
Cost of revenue (exclusive of amortization of acquired intangible assets)	268,582		276,804		283,439		303,847
Net income	123,146		161,915		158,623		113,370
Basic net income per share	0.76		1.00		0.97		0.70
Diluted net income per share	0.75		0.98		0.95		0.68
Year ended December 31, 2019:
Revenue	$	706,508	$	705,074	$	709,912	$	772,123
Cost of revenue (exclusive of amortization of acquired intangible assets)	240,743		242,193		246,938		257,750
Net income	107,130		113,915		137,890		119,100
Basic net income per share	0.66		0.70		0.85		0.74
Diluted net income per share	0.65		0.69		0.84		0.73

Goodwill and Acquired Intangible Assets

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Acquired Intangible Assets

Acquired intangible assets that are subject to amortization consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020						December 31, 2019
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Completed technologies	$	172,346	$	(111,435)	$	60,911	$	153,722	$	(94,088)	$	59,634
Customer-related intangible assets	358,032		(186,733)		171,299		279,684		(163,155)		116,529
Non-compete agreements	373		(77)		296		830		(529)		301
Trademarks and trade names	7,658		(5,440)		2,218		7,600		(4,633)		2,967
Acquired license rights	490		(490)		—		490		(490)		—
Total	$	538,899	$	(304,175)	$	234,724	$	442,326	$	(262,895)	$	179,431

Aggregate expense related to amortization of acquired intangible assets for the years ended December 31, 2020, 2019 and 2018 was $42.0 million, $38.6 million and $33.3 million, respectively. Based on the Company's acquired intangible assets as of December 31, 2020, aggregate expense related to amortization of acquired intangible assets is expected to be $47.4 million, $43.8 million, $36.3 million, $28.4 million and $22.9 million for the years ending December 31, 2021, 2022, 2023, 2024 and 2025, respectively.

The changes in the carrying amount of goodwill for the years ended December 31, 2020 and 2019 were as follows (in thousands):


	2020		2019
Beginning balance	$	1,600,265	$	1,487,404
Acquisition of Asavie Technologies Limited	70,200		—
Acquisition of Janrain, Inc.	—		92,188
Acquisition of Exceda	—		14,712
Acquisition of ChameleonX, Ltd.	—		7,069
Measurement period adjustments related to acquisitions completed in prior years	(1,056)		—
Foreign currency translation	4,962		(1,108)
Ending balance	$	1,674,371	$	1,600,265

Revenue from Contracts with Customers

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Revenue from Contracts with Customers

The Company sells its services through a sales force located both domestically and abroad. Revenue derived from operations outside of the U.S. is determined based on the country in which the sale originated. Other than the U.S., no single country accounted for 10% or more of the Company’s total revenue for any reported period. The following table summarizes revenue by geography included in the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
U.S.	$	1,777,435	$	1,694,211	$	1,683,272
International	1,420,714		1,199,406		1,031,202
Total revenue	$	3,198,149	$	2,893,617	$	2,714,474

While the Company sells its services through a geographically dispersed sales force, it manages its customer relationships in two divisions: the Web Division and the Media and Carrier Division. Revenue by division is a customer-focused reporting view that reflects revenue from customers that are managed by the division. Customers are assigned to a division for relationship management purposes according to their predominant purchasing activity; however, customers may purchase solutions managed by the other division as well. The following table summarizes revenue by division included in the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Web Division	$	1,666,305	$	1,556,252	$	1,439,772
Media and Carrier Division	1,531,844		1,337,365		1,274,702
Total revenue	$	3,198,149	$	2,893,617	$	2,714,474

As the purchasing patterns and required account expertise of customers change over time, the Company may reassign a customer from one division to another. In 2020, the Company reassigned some customers between the Media and Carrier Division and the Web Division and revised historical results in order to reflect the most recent categorization and to provide a comparable view for all periods presented.

Most content delivery and security services represent obligations that are satisfied over time as the customer simultaneously receives and consumes the services provided by the Company. Accordingly, the majority of the Company's revenue is recognized over time, generally ratably over the term of the arrangement due to consistent monthly traffic commitments that expire each period. A small percentage of the Company's services are satisfied at a point in time, such as one-time professional services contracts, integration services and most license sales where the primary obligation is delivery of the license at the start of the term. In these cases, revenue is recognized at a point in time of delivery or satisfaction of the performance obligation.

During the years ended December 31, 2020 and 2019, the Company recognized $69.9 million and $64.1 million of revenue that was included in deferred revenue as of December 31, 2019 and 2018, respectively.

As of December 31, 2020, the aggregate amount of remaining performance obligations from contracts with customers was $2.9 billion. The Company expects to recognize approximately 70% of its remaining performance obligations as revenue over the next 12 months, with the remaining recognized thereafter. Remaining performance obligations represent the amount of the transaction price under contracts with customers that are attributable to performance obligations that are unsatisfied or partially satisfied at the reporting date. This consists of future committed revenue for monthly, quarterly or annual periods within current contracts with customers, as well as deferred revenue arising from consideration invoiced in prior periods for which the related performance obligations have not been satisfied. It excludes estimates of variable consideration such as usage-based contracts with no committed contract as well as anticipated contract renewals.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130550-203045

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

+ Details

Property and Equipment

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment consisted of the following as of December 31, 2020 and 2019 (in thousands except years):


	December 31, 2020		December 31, 2019		Estimated Useful Life (in years)
Computer and networking equipment	$	1,847,717	$	1,469,293	3-7
Purchased software	95,662		90,450		3-10
Furniture and fixtures	71,119		65,683		1-7
Office equipment	40,235		38,178		3-5
Leasehold improvements	230,423		235,279		1-15
Internal-use software	1,234,934		1,132,180		2-7
Property and equipment, gross	3,520,090		3,031,063
Accumulated depreciation and amortization	(2,041,818)		(1,878,910)
Property and equipment, net	$	1,478,272	$	1,152,153

Depreciation and amortization expense on property and equipment and capitalized internal-use software for the years ended December 31, 2020, 2019 and 2018 was $436.3 million, $402.1 million and $401.2 million, respectively. During the years ended December 31, 2020, 2019 and 2018, the Company capitalized $38.0 million, $35.9 million and $34.8 million, respectively, of stock-based compensation related to employees who developed and enhanced internal-use software applications.

During the years ended December 31, 2020 and 2019, the Company wrote off $279.9 million and $166.7 million, respectively, of property and equipment, gross, along with the associated accumulated depreciation and amortization. The write-

offs were primarily related to leasehold improvements, computer and networking equipment and internal-use software no longer in use. These assets had been substantially depreciated and amortized. In addition, the Company wrote off $0.8 million and $3.8 million, primarily of internal-use software as a result of certain restructuring efforts during the year ended December 31, 2020 and December 31, 2019, respectively.

Leases

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Leases

The Company has entered into various operating lease agreements for its offices and co-location assets and related equipment. The Company has also entered into sublease agreements with tenants of various offices previously vacated by the Company. These operating leases have lease periods expiring between 2021 and 2034. The following table is a summary of the Company’s operating lease costs for the years ended December 31, 2020 and 2019 (in thousands):


	December 31, 2020						December 31, 2019
	Real Estate Arrangements		Co-location Arrangements		Total		Real Estate Arrangements		Co-location Arrangements		Total
Operating lease cost	$	83,574	$	113,554	$	197,128	$	63,893	$	96,020	$	159,913
Short-term lease cost	229		15,620		15,849		111		14,301		14,412
Variable lease cost	21,235		34,259		55,494		15,610		23,524		39,134
Sublease income	(22,064)		—		(22,064)		(5,119)		—		(5,119)
Total operating lease costs	$	82,974	$	163,433	$	246,407	$	74,495	$	133,845	$	208,340

Real estate rent expense and sublease income for the year ended December 31, 2018 were $63.2 million and $3.8 million, respectively. Lease costs for real estate arrangements are included in general and administrative expenses in the consolidated statements of income. Lease costs for co-location arrangements are primarily included in cost of revenue.

At December 31, 2020 and 2019, the real estate arrangements' weighted average remaining lease term was 11.8 years and 12.8 years, respectively, and the weighted average discount rate for operating leases was 3.4% and 3.5%, respectively. At December 31, 2020 and 2019, the co-location arrangements' weighted average remaining lease term was 4.3 years and 3.9 years, respectively, and the weighted average discount rate for operating leases was 1.8% and 2.2%, respectively.

Maturities of operating lease liabilities as of December 31, 2020 were as follows (in thousands):


	Real Estate Arrangements		Co-location Arrangements
2021	$	80,787	$	73,540
2022	83,863		36,805
2023	79,445		23,396
2024	70,967		16,815
2025	66,209		10,775
Thereafter	473,558		25,208
Total lease payments	854,829		186,539
Less: imputed interest	162,588		8,575
Total lease liabilities	$	692,241	$	177,964

As of December 31, 2020, the Company had additional operating leases, primarily for co-location arrangements, that had not yet commenced of $13.6 million, which will commence in 2021 and 2022, with lease terms of one year to seven years. The table above excludes approximately $216.7 million of future sublease income that is expected to be recognized through 2034.

As of December 31, 2020, the Company had outstanding letters of credit in the amount of $5.8 million, primarily related to operating leases. The letters of credit remain in effect until the Company fulfills its obligations under these leases or as such obligations expire under the terms of the letters of credit.

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 3,198,149	$ 2,893,617	$ 2,714,474
Costs and operating expenses:
Cost of revenue (exclusive of amortization of acquired intangible assets shown below)	1,132,672	987,624	953,485
Research and development	269,315	261,365	246,165
Sales and marketing	510,405	523,883	517,353
General and administrative	547,888	516,093	574,067
Amortization of acquired intangible assets	42,049	38,581	33,311
Restructuring charge	37,286	17,153	27,594
Total costs and operating expenses	2,539,615	2,344,699	2,351,975
Income from operations	658,534	548,918	362,499
Interest income	29,122	34,355	26,940
Interest expense	(69,120)	(49,364)	(43,202)
Other expense, net	(2,454)	(1,428)	(3,148)
Income before provision for income taxes	616,082	532,481	343,089
Provision for income taxes	(45,922)	(53,350)	(44,716)
Loss from equity method investment	(13,106)	(1,096)	0
Net income	$ 557,054	$ 478,035	$ 298,373
Net income per share:
Basic (in dollars per share)	$ 3.43	$ 2.94	$ 1.78
Diluted (in dollars per share)	$ 3.37	$ 2.90	$ 1.76
Shares used in per share calculations:
Basic (in shares)	162,490	162,706	167,312
Diluted (in shares)	165,213	164,573	169,188

Fair Value Measurements - Narrative (Details) $ in Millions	Dec. 31, 2020 USD ($)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position for more than 12 months	$ 2.0

Debt - Narrative (Details) $ / shares in Units, shares in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2019 USD ($) d $ / shares shares	May 31, 2018 USD ($) d $ / shares shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Feb. 28, 2014 USD ($)
Debt Instrument [Line Items]
Closing stock price (in dollars per share) \| $ / shares			$ 104.99
Repurchases of common stock			$ 193,588,000	$ 334,519,000	$ 750,000,000
Payments for note hedge transactions			0	312,225,000	261,740,000
Proceeds from sale of warrants			0	185,150,000	$ 119,945,000
Convertible Debt \| 2027 Notes
Debt Instrument [Line Items]
Debt issued	$ 1,150,000,000.0		$ 1,150,000,000	1,150,000,000
Interest rate	0.375%		0.375%
Threshold trading days exceeding price \| d	20
Threshold consecutive trading days exceeding price \| d	30
Threshold greater than percentage of stock price trigger	130.00%
Threshold trading days not exceeding price	5 days
Threshold consecutive trading days not exceeding price	5 days
Threshold less than percentage of stock price trigger	98.00%
Conversion rate	0.0086073
Conversion price (in dollars per share) \| $ / shares	$ 116.18
Potential conversion shares of convertible debt (in shares) \| shares	9.9
Fair value of convertible senior notes			$ 1,277,800,000
Closing stock price (in dollars per share) \| $ / shares			$ 104.99
Repurchases of common stock	$ 100,000,000.0
Payments for purchase of convertible note hedge and warrant transactions	127,100,000
Payments for note hedge transactions	$ 312,200,000
Warrants outstanding (in shares) \| shares	9.9
Warrant strike price (in dollars per share) \| $ / shares	$ 178.74
Proceeds from sale of warrants	$ 185,200,000
Effective interest rate			3.10%
Convertible Debt \| 2025 Notes
Debt Instrument [Line Items]
Debt issued		$ 1,150,000,000.0	$ 1,150,000,000	$ 1,150,000,000
Interest rate		0.125%	0.125%
Threshold trading days exceeding price \| d		20
Threshold consecutive trading days exceeding price \| d		30
Threshold greater than percentage of stock price trigger		130.00%
Threshold trading days not exceeding price		5 days
Threshold consecutive trading days not exceeding price		5 days
Threshold less than percentage of stock price trigger		98.00%
Conversion rate		0.010515
Conversion price (in dollars per share) \| $ / shares		$ 95.10
Potential conversion shares of convertible debt (in shares) \| shares		12.1
Fair value of convertible senior notes			$ 1,422,800,000
Closing stock price (in dollars per share) \| $ / shares			$ 104.99
Repurchases of common stock		$ 46,200,000
Payments for purchase of convertible note hedge and warrant transactions		141,800,000
Payments for note hedge transactions		$ 261,700,000
Warrants outstanding (in shares) \| shares		12.1
Warrant strike price (in dollars per share) \| $ / shares		$ 149.18
Proceeds from sale of warrants		$ 119,900,000
Effective interest rate			4.26%
Convertible Debt \| 2019 Notes
Debt Instrument [Line Items]
Debt issued						$ 690,000,000.0
Effective interest rate			3.20%

Goodwill and Acquired Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquired intangible assets	$ 42,049	$ 38,581	$ 33,311
2021	47,400
2022	43,800
2023	36,300
2024	28,400
2025	$ 22,900

Accrued Expenses

12 Months Ended

Dec. 31, 2020

Accounts Payable and Accrued Liabilities, Current [Abstract]

Accrued Expenses

Accrued expenses consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Payroll and other related benefits	$	218,588	$	190,721
Bandwidth and co-location	67,170		65,213
Income tax payable	50,812		40,337
Property, use and other taxes	35,390		30,904
Professional service fees	2,245		1,775
Other accrued expenses	6,263		5,911
Total	$	380,468	$	334,861

Fair Value Measurements - Schedule of Contractual Maturities of Marketable Securities and Other Investment Related Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Due in 1 year or less	$ 744,290	$ 1,143,006
Due after 1 year through 5 years	1,379,736	820,450
Aggregate Fair Value	$ 2,124,026	$ 1,963,456

Stock-Based Compensation

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

Equity Plans

In May 2013, the Company's stockholders approved the Akamai Technologies, Inc. 2013 Stock Incentive Plan (as amended in 2015, 2017 and 2019, the "2013 Plan"). The 2013 Plan replaced the Akamai Technologies, Inc. 2009 Stock Incentive Plan (the "2009 Plan"), which in turn replaced the Akamai Technologies, Inc. 2006 Stock Incentive Plan, the Akamai Technologies, Inc. 2001 Stock Incentive Plan and the Akamai Technologies, Inc. 1998 Stock Incentive Plan (together with the 2009 Plan, the "Previous Plans"). The Company no longer issues equity awards under the Previous Plans, and they solely exist to satisfy outstanding equity awards previously granted under those plans. The 2013 Plan allows for the issuance of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, other stock-based awards and cash-based awards up to 21.5 million shares of common stock to employees, officers, directors, consultants and advisers of the Company. Additionally, the Company may grant up to 3.8 million shares of common stock thereunder that were available for grant under the 2009 Plan immediately prior to stockholder approval of the 2013 Plan. Any shares of common stock that are currently outstanding under the Previous Plans that are terminated, canceled, surrendered or forfeited will become available to grant under the 2013 Plan. As of December 31, 2020, the Company had reserved approximately 6.5 million shares of common stock available for future issuance of equity awards under the 2013 Plan.

The Company has assumed certain stock option plans and the outstanding stock options of companies that it has acquired (“Assumed Plans”). Stock options outstanding as of the date of acquisition under the Assumed Plans were exchanged for the Company’s stock options and adjusted to reflect the appropriate conversion ratio as specified by the applicable acquisition agreement, but are otherwise administered in accordance with the terms of the Assumed Plans. Stock options under the Assumed Plans generally vest over four years and expire ten years from the date of grant.

The 1999 Employee Stock Purchase Plan ("1999 ESPP") permits eligible employees to purchase up to 1.5 million shares each June 1 and December 1, provided that the aggregate number of shares issued shall not exceed 20.0 million. The 1999 ESPP allows participants to purchase shares of common stock at a 15% discount from the fair market value of the stock as determined on specific dates at six-month intervals. During the years ended December 31, 2020, 2019 and 2018, the Company issued 0.7 million, 0.9 million and 1.0 million shares under the 1999 ESPP, respectively, with a weighted average purchase price per share of $80.71, $61.04 and $52.04, respectively. Total cash proceeds from the purchase of shares under the 1999 ESPP in the years ended December 31, 2020, 2019 and 2018 were $58.4 million, $53.7 million and $50.7 million, respectively.

As of December 31, 2020, approximately $5.9 million had been withheld from employees for future purchases under the 1999 ESPP.

Stock-Based Compensation Expense


	2020		2019		2018
Cost of revenue	$	24,829	$	22,479	$	21,892
Research and development	48,855		49,685		44,034
Sales and marketing	65,257		62,150		64,373
General and administrative	58,470		52,826		53,514
Total stock-based compensation	197,411		187,140		183,813
Provision for income taxes	(62,153)		(51,177)		(48,502)
Total stock-based compensation, net of taxes	$	135,258	$	135,963	$	135,311

In addition to the amounts of stock-based compensation reported in the table above, the Company’s consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 also include stock-based compensation reflected as a component of amortization of capitalized internal-use software; the additional stock-based compensation was $29.6 million, $30.6 million and $25.2 million, respectively, before taxes.

The Company uses the Black-Scholes option pricing model to determine the fair value of the Company’s stock option awards. This model requires the input of subjective assumptions, including expected stock price volatility and the estimated term of each award. The estimated fair value of the Company's stock-based awards, less expected forfeitures, is amortized over the awards’ vesting period on a straight-line basis. Expected volatilities are based on the Company’s historical stock price volatility and implied volatility from traded options in its stock. The Company uses historical data to estimate the expected term of options granted within the valuation model. The risk-free interest rate for periods commensurate with the expected term of the option is based on the U.S. Treasury yield rate in effect at the time of grant. The expected dividend yield is zero, as the Company currently does not pay a dividend and does not anticipate doing so in the future.


	2020		2019		2018
Expected term (in years)	0.5		0.5		0.5
Risk-free interest rate	0.7	%	2.3	%	1.9	%
Expected volatility	30.4	%	29.6	%	31.2	%
Dividend yield	—	%	—	%	—	%

For the years ended December 31, 2020, 2019 and 2018, the weighted average fair value of awards granted under the 1999 ESPP was $32.30 per share, $20.90 per share and $15.29 per share, respectively.

As of December 31, 2020, total pre-tax unrecognized compensation cost for stock options, restricted stock units, deferred stock units and shares of common stock issued under the 1999 ESPP was $274.5 million. The expense is expected to be recognized through 2024 over a weighted average period of 1.6 years.

Stock Options

The following table summarizes stock option activity during the year ended December 31, 2020:


	Shares (in thousands)	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2020	20	$	26.23
Exercised	(14)	32.85


Outstanding at December 31, 2020	6	$	11.60	1.09	$	595
Exercisable at December 31, 2020	6	$	11.60	1.09	$	595
Vested or expected to vest December 31, 2020	6	$	11.60	1.09	$	595

The total pre-tax intrinsic value of options exercised during the years ended December 31, 2020, 2019 and 2018 was $1.0 million, $3.9 million and $8.2 million, respectively. The total fair value of options vested for the years ended December 31, 2020 and 2019 was insignificant.

The aggregate intrinsic value in the preceding table represents the total pre-tax intrinsic value, based on the Company’s closing stock price of $104.99 on December 31, 2020, that would have been received by the option holders had all option holders exercised their “in-the-money” options as of that date. The total number of shares issuable upon the exercise of “in-the-money” options exercisable as of December 31, 2020 was 6,371.

Deferred Stock Units

The Company has granted deferred stock units ("DSUs") to non-employee members of its board of directors. Each DSU represents the right to receive one share of the Company’s common stock upon vesting. The holder may elect to defer receipt of the vested shares of stock represented by the DSU for a period of at least one year but not more than ten years from the grant date. DSUs vest 100% on the first anniversary of the grant date. If a director has completed one year of Board service, vesting of 100% of the DSUs held by such director will accelerate at the time of his or her departure from the Board.

The following table summarizes the DSU activity for the year ended December 31, 2020:


	Units (in thousands)	Weighted Average Grant Date Fair Value
Outstanding at January 1, 2020	99	$	57.50
Granted	24	100.58
Vested and distributed	(9)	76.62
Outstanding at December 31, 2020	114	$	65.09

The total pre-tax intrinsic value of DSUs that were vested and distributed during the years ended December 31, 2020, 2019 and 2018 was $0.9 million, $7.7 million and $3.0 million, respectively. The total fair value of DSUs that were vested and distributed during the years ended December 31, 2020, 2019 and 2018 was $0.7 million, $4.9 million and $1.8 million, respectively. The grant-date fair value is calculated based upon the Company’s closing stock price on the date of grant. As of December 31, 2020, 23,908 DSUs were unvested, with an aggregate intrinsic value of approximately $2.5 million and a weighted average remaining contractual life of approximately 0.3 years. These units are expected to vest in May 2021.

Restricted Stock Units

The following table summarizes the different types of restricted stock units ("RSUs") granted by the Company during the year ended December 31, 2020 (in thousands):


			December 31, 2020
RSUs with service-based vesting conditions			2,223
RSUs with market-based vesting conditions			91
RSUs with performance-based vesting conditions			396
Total			2,710

RSUs represent the right to receive one share of the Company’s common stock upon vesting. RSUs are granted at the discretion of the board of directors, a committee thereof or, subject to defined limitations, the Chief Executive Officer of the Company, acting as a committee of one director, to whom such authority has been delegated. The Company has issued RSUs that vest based on the passage of time assuming continued service with the Company, RSUs that vest only upon the achievement of defined performance metrics tied primarily to revenue and earnings targets, and RSUs that vest based upon total shareholder return ("TSR") measured against the benchmark TSR of a peer group.

For RSUs with service-based vesting conditions, the fair value is calculated based upon the Company’s closing stock price on the date of grant, and the stock-based compensation expense is being recognized over the vesting period. Most RSUs with service-based vesting provisions vest in installments over a three- or four-year period following the grant date.

The Company uses the Monte Carlo simulation model to determine the fair value of the Company's RSUs based on TSR. This model requires the input of assumptions, including the estimated term of each award, the risk-free interest rate, historical stock price volatility of the Company's shares and historical stock price volatility of peer-company shares. The grant-date fair values of the TSR-based RSUs granted during the years ended December 31, 2020, 2019 and 2018 were estimated using a Monte Carlo simulation model with the following assumptions:


	2020		2019		2018
Expected term (in years)	3.0		3.0		3.0
Risk-free interest rate	0.7	%	2.5	%	2.3	%
Akamai historical share price volatility	28.2	%	32.8	%	35.5	%
Average volatility of peer-company share price	28.9	%	27.0	%	26.3	%

For the years ended December 31, 2020, 2019 and 2018, management measured compensation expense for performance-based RSUs based upon a review of the Company’s expected achievement against specified financial performance targets. Such compensation cost is being recorded using a graded-vesting method for each series of grants of performance-based RSUs, to the extent management has deemed that such awards are probable of vesting based upon the expected achievement against the specified targets. On a periodic basis, management reviews the Company’s expected performance and adjusts the compensation cost, if needed, at such time.

The following table summarizes the RSU activity for the year ended December 31, 2020:


	Units (in thousands)	Weighted Average Grant Date Fair Value
Outstanding at January 1, 2020	5,073	$	70.43
Granted	2,710	92.42
Vested	(2,881)	69.04
Forfeited	(346)	75.55
Outstanding at December 31, 2020	4,556	$	83.96

The total pre-tax intrinsic value of RSUs that vested during the years ended December 31, 2020, 2019 and 2018 was $192.5 million, $189.4 million and $173.6 million, respectively. The total fair value of RSUs that vested during the years ended December 31, 2020, 2019 and 2018 was $198.9 million, $195.5 million and $178.3 million, respectively. The grant-date fair value of each RSU is calculated based upon the Company’s closing stock price on the date of grant. As of December 31, 2020, 4.6 million RSUs were outstanding and unvested, with an aggregate intrinsic value of $478.5 million and a weighted average remaining vesting period of approximately 1.5 years. These RSUs are expected to vest on various dates through 2024.

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2017			169,893,324
Beginning Balance at Dec. 31, 2017	$ 3,362,469	$ (38,601)	$ 1,699	$ 4,073,362	$ 0	$ (21,930)	$ (690,662)	$ (38,601)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes (in shares)			2,235,212
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes	(56,544)		$ 22	(56,566)
Issuance of common stock under employee stock purchase plan (in shares)			973,975
Issuance of common stock under employee stock purchase plan	50,688		$ 10	50,678
Stock-based compensation	218,416			218,416
Equity component of convertible senior notes, net of deferred tax of $4,971 and issuance costs of $4,418	275,836			275,836
Issuance of warrants related to convertible senior notes	119,945			119,945
Purchase of note hedge related to convertible senior notes	(261,740)			(261,740)
Repurchases of common stock (in shares)			(10,197,961)
Repurchases of common stock	(750,000)				(750,000)
Treasury stock retirement	0		$ (102)	(749,898)	750,000
Net income	298,373						298,373
Foreign currency translation adjustments	(27,585)					(27,585)
Change in unrealized gain on investments, net of tax	603					603
Ending balance (in shares) at Dec. 31, 2018			162,904,550
Ending Balance at Dec. 31, 2018	3,191,860	$ 851	$ 1,629	3,670,033	0	(48,912)	(430,890)	$ 851
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes (in shares)			2,251,840
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes	(72,328)		$ 22	(72,350)
Issuance of common stock under employee stock purchase plan (in shares)			879,648
Issuance of common stock under employee stock purchase plan	53,689		$ 9	53,680
Stock-based compensation	222,857			222,857
Equity component of convertible senior notes, net of deferred tax of $4,971 and issuance costs of $4,418	240,820			240,820
Issuance of warrants related to convertible senior notes	185,150			185,150
Purchase of note hedge related to convertible senior notes	(312,225)			(312,225)
Repurchases of common stock (in shares)			(4,035,195)
Repurchases of common stock	(334,519)				(334,519)
Treasury stock retirement	0		$ (40)	(334,479)	334,519
Net income	478,035						478,035
Foreign currency translation adjustments	(1,020)					(1,020)
Change in unrealized gain on investments, net of tax	4,788					4,788
Ending balance (in shares) at Dec. 31, 2019			162,000,843
Ending Balance at Dec. 31, 2019	3,657,958		$ 1,620	3,653,486	0	(45,144)	47,996
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes (in shares)			1,949,963
Issuance of common stock upon the exercise of stock options and vesting of restricted and deferred stock units, net of shares withheld for employee taxes	(89,102)		$ 20	(89,122)
Issuance of common stock under employee stock purchase plan (in shares)			723,600
Issuance of common stock under employee stock purchase plan	58,402		$ 7	58,395
Stock-based compensation	235,629			235,629
Repurchases of common stock (in shares)			(1,964,686)
Repurchases of common stock	(193,588)				(193,588)
Treasury stock retirement	0		$ (20)	(193,568)	193,588
Net income	557,054						557,054
Foreign currency translation adjustments	19,629					19,629
Change in unrealized gain on investments, net of tax	5,314					5,314
Ending balance (in shares) at Dec. 31, 2020			162,709,720
Ending Balance at Dec. 31, 2020	$ 4,251,296		$ 1,627	$ 3,664,820	$ 0	$ (20,201)	$ 605,050

Nature of Business and Basis of Presentation	12 Months Ended
Nature of Business and Basis of Presentation	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Nature of Business and Basis of Presentation Akamai Technologies, Inc. (the “Company”) provides solutions for securing, delivering and optimizing content and business applications over the internet. Its globally-distributed platform comprises more than 325,000 servers across more than 130 countries. The Company was incorporated in Delaware in 1998 and is headquartered in Cambridge, Massachusetts. The Company currently operates in one industry segment: providing cloud services for delivering, optimizing and securing content and business applications over the internet. The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in the accompanying consolidated financial statements.

Fair Value Measurements - Schedule of Fair Value Measurement (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash Equivalents and Marketable Securities:
Available-for-sale securities	$ 2,124,026	$ 1,963,456
Total Fair Value	2,247,224	2,029,412
Money market funds
Cash Equivalents and Marketable Securities:
Cash equivalents	74,417	50,779
Certificates of deposit
Cash Equivalents and Marketable Securities:
Available-for-sale securities		150,000
Commercial paper
Cash Equivalents and Marketable Securities:
Available-for-sale securities	46,936	73,845
Available-for-sale securities and cash equivalents	75,785
Corporate bonds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	1,637,682	1,370,130
Municipal securities
Cash Equivalents and Marketable Securities:
Available-for-sale securities	3,489
U.S. government agency obligations
Cash Equivalents and Marketable Securities:
Available-for-sale securities	435,919	369,481
Available-for-sale securities and cash equivalents	435,919
Mutual funds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	19,932	15,177
Level 1
Cash Equivalents and Marketable Securities:
Total Fair Value	94,349	65,956
Level 1 \| Money market funds
Cash Equivalents and Marketable Securities:
Cash equivalents	74,417	50,779
Level 1 \| Certificates of deposit
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Level 1 \| Commercial paper
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Available-for-sale securities and cash equivalents	0
Level 1 \| Corporate bonds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	0	0
Level 1 \| Municipal securities
Cash Equivalents and Marketable Securities:
Available-for-sale securities	0
Level 1 \| U.S. government agency obligations
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Available-for-sale securities and cash equivalents	0
Level 1 \| Mutual funds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	19,932	15,177
Level 2
Cash Equivalents and Marketable Securities:
Total Fair Value	2,152,875	1,963,456
Level 2 \| Money market funds
Cash Equivalents and Marketable Securities:
Cash equivalents	0	0
Level 2 \| Certificates of deposit
Cash Equivalents and Marketable Securities:
Available-for-sale securities		150,000
Level 2 \| Commercial paper
Cash Equivalents and Marketable Securities:
Available-for-sale securities		73,845
Available-for-sale securities and cash equivalents	75,785
Level 2 \| Corporate bonds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	1,637,682	1,370,130
Level 2 \| Municipal securities
Cash Equivalents and Marketable Securities:
Available-for-sale securities	3,489
Level 2 \| U.S. government agency obligations
Cash Equivalents and Marketable Securities:
Available-for-sale securities		369,481
Available-for-sale securities and cash equivalents	435,919
Level 2 \| Mutual funds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	0	0
Level 3
Cash Equivalents and Marketable Securities:
Total Fair Value	0	0
Level 3 \| Money market funds
Cash Equivalents and Marketable Securities:
Cash equivalents	0	0
Level 3 \| Certificates of deposit
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Level 3 \| Commercial paper
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Available-for-sale securities and cash equivalents	0
Level 3 \| Corporate bonds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	0	0
Level 3 \| Municipal securities
Cash Equivalents and Marketable Securities:
Available-for-sale securities	0
Level 3 \| U.S. government agency obligations
Cash Equivalents and Marketable Securities:
Available-for-sale securities		0
Available-for-sale securities and cash equivalents	0
Level 3 \| Mutual funds
Cash Equivalents and Marketable Securities:
Available-for-sale securities	$ 0	$ 0

Stock-Based Compensation - Schedule of Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Shares
Outstanding (in shares) \| shares	20
Exercised (in shares) \| shares	(14)
Outstanding (in shares) \| shares	6
Exercisable (in shares) \| shares	6
Vested or expected to vest (in shares) \| shares	6
Weighted Average Exercise Price
Outstanding (in dollars per share) \| $ / shares	$ 26.23
Exercised (in dollars per share) \| $ / shares	32.85
Outstanding (in dollars per share) \| $ / shares	11.60
Exercisable (in dollars per share) \| $ / shares	11.60
Vested or expected to vest (in dollars per share) \| $ / shares	$ 11.60
Weighted Average Remaining Contractual Term & Aggregate Intrinsic Value
Outstanding	1 year 1 month 2 days
Exercisable	1 year 1 month 2 days
Vested or expected to vest	1 year 1 month 2 days
Outstanding \| $	$ 595
Exercisable \| $	595
Vested or expected to vest \| $	$ 595

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Schedule of Long-Term Commitments

The minimum future commitments as of December 31, 2020 were as follows (in thousands):


	Bandwidth Commitments		Purchase Order Commitments
2021	$	95,923	$	231,059
2022	19,046		22,014
2023	4,186		9,640
2024	120		3,931
2025	120		—
Thereafter	100		—
Total	$	119,495	$	266,644

Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Taxes

The components of income before provision for income taxes were as follows for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
U.S.	$	45,074	$	24,253	$	(27,379)
Foreign	571,008		508,228		370,468
Income before provision for income taxes	$	616,082	$	532,481	$	343,089

The provision for income taxes consisted of the following for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Current tax (benefit) provision:
Federal	$	(1,765)	$	(22,704)	$	(29,982)
State	5,346		3,835		8,085
Foreign	76,162		71,286		64,274
Deferred tax (benefit) provision:
Federal	(19,845)		(13,987)		5,954
State	(14,509)		(12,212)		701
Foreign	(6,023)		4,968		(7,140)
Change in valuation allowance	6,556		22,164		2,824
Total	$	45,922	$	53,350	$	44,716

The Company’s effective tax rate differed from the U.S. federal statutory tax rate as follows for the years ended December 31, 2020, 2019 and 2018:


	2020		2019		2018
U.S. federal income tax rate	21.0	%	21.0	%	21.0	%
State taxes	1.0		1.0		1.2
Stock-based compensation	(0.6)		0.3		1.0
U.S. federal, state and foreign research and development credits	(4.4)		(6.0)		(7.6)
Foreign earnings	(7.7)		(6.1)		(6.0)

Nondeductible (nontaxable) foreign items	(0.4)		0.7		0.4
Impact of U.S. Tax Cuts and Jobs Act, net	—		—		(0.8)


Release of uncertain tax position reserve	(0.9)		(5.9)		(1.9)

Intercompany sale of intellectual property	0.2		1.9		3.3
Valuation allowance	1.1		4.2		0.8
Other	(1.8)		(1.1)		1.6
	7.5	%	10.0	%	13.0	%

The components of the net deferred tax assets and liabilities and the related valuation allowance as of December 31, 2020 and 2019 were as follows (in thousands):


	2020		2019
Accrued bonus	$	25,480	$	25,487
Deferred revenue	11,146		3,874

Operating lease liability	141,212		147,375
Stock-based compensation	23,629		20,606
NOLs	25,255		25,851
Unrealized losses	—		1,529
Tax credit carryforwards	110,254		87,305

Convertible senior notes interest	20,953		22,506
Other	11,531		12,501
Deferred tax assets	369,460		347,034
Depreciation and amortization	(6,974)		(16,896)

Acquired intangible assets	(59,128)		(51,758)

Operating lease right-of-use asset	(127,524)		(132,949)
Deferred commissions	(14,952)		(14,843)
Internal-use software development costs capitalized	(58,820)		(57,201)

Deferred tax liabilities	(267,398)		(273,647)
Valuation allowance	(32,602)		(26,046)
Net deferred tax assets	$	69,460	$	47,341

Valuation allowances will be recognized on deferred tax assets if it is more-likely-than-not that some or all of the deferred tax assets will not be utilized. In measuring deferred tax assets, the Company considers all available evidence, both positive and negative, to determine whether a valuation allowance is needed. As of December 31, 2020, the Company recorded a $32.6 million valuation allowance against deferred tax assets related to tax credits and state and foreign NOLs in which it is more-likely-than-not that such attributes will expire prior to utilization. The change in the valuation allowance during 2020 was $6.6 million.

The table below summarizes the Company's NOL and tax credit carryforwards in federal, state and foreign jurisdictions as of December 31, 2020 and 2019 (in thousands, except for years):


	2020		2019		Expirations at Various Dates Through:
NOL carryforwards:
Federal	$	59,200	$	87,500	2037
State	24,800		20,500		2040
Foreign	40,800		11,600		—
Federal and state research and development tax credit and other credit carryforwards	132,800		88,570		2034

The Company's U.S. federal and state NOL carryforwards relate to acquisitions completed in 2019, 2017 and 2012. Foreign NOL carryforwards relate to losses due to the difference in local tax laws.

As of December 31, 2020, accumulated earnings outside the U.S. totaled $985.7 million, the majority of which have been taxed due to the one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings and the tax on global intangible low taxed income required by the U.S. Tax Cuts and Jobs Act ("TCJA"). No provision for U.S. income and foreign withholding taxes has been provided for any remaining undistributed foreign earnings not subject to tax under the TCJA, or any additional basis differences inherent in these entities, as these amounts continue to be indefinitely reinvested. Determination of the amount of the unrecognized deferred tax liability on outside basis differences is not practicable because of the complexity of laws and regulations, the varying tax treatment of alternative repatriation scenarios and the variation due to multiple potential assumptions relating to the timing of any future repatriation.

The following is a roll forward of the Company’s unrecognized tax benefits for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Balance at beginning of year	$	27,359	$	64,892	$	85,845
Gross increases – tax positions of prior periods	2,539		74		2,704
Gross increases – current period tax positions	1,946		2,006		3,021
Gross decreases – tax positions of prior periods	(3,540)		(5,201)		(15,287)
Gross decreases – lapse of applicable statute of limitations	(4,199)		(28,672)		(6,186)
Gross decreases – settlements	—		(5,740)		(5,205)
Balance at end of year	$	24,105	$	27,359	$	64,892

As of December 31, 2020, 2019 and 2018, the Company had $29.5 million, $32.6 million and $67.8 million of unrecognized tax benefits, respectively. Total interest and penalties for unrecognized tax benefits include $7.7 million, $7.8 million and $11.8 million as of December 31, 2020, 2019 and 2018, respectively. Interest and penalties related to unrecognized tax benefits are recorded in the provision for income taxes and were $1.2 million, $1.1 million and $1.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. The amount of unrecognized tax benefits that, if recognized, would impact the effective income tax rate is approximately $29.5 million.

As of December 31, 2020, it is reasonably possible that $9.6 million of unrecognized tax benefits may be recognized within the next 12 months due to the expiration of local statutes of limitations. Certain U.S. state and foreign income tax returns from 2011 through 2019 are currently under audit. The Company has reserved for those positions that are not more-likely-than-not to be sustained.

The Company is also involved in litigation related to certain adverse audit determinations. In the second quarter of 2018, the Company filed an appeal with the Massachusetts Appellate Tax Board contesting the adverse audit findings related to certain tax benefits and exemptions. The appeal hearing was held in late 2019. In July 2020, the Massachusetts Appellate Tax Board ruled in the Company's favor; however the decision is eligible for appeal by the Massachusetts Department of Revenue. The Company has determined that it is more-likely-than-not that it will prevail, and no reserve has been recorded related to these controversies. However, over the next 12 months, the Company's current assumptions and positions could change based on potential appeal decisions and other events impacting its analysis. Such events, if resolved unfavorably, could significantly impact the Company’s effective income tax rate and results of operations. The Company has estimated that an adverse ruling related to its Massachusetts controversy could result in an gross income tax charge of approximately $41.0 million, which could be partially offset by certain state tax credits of $27.0 million which are not currently benefited as a result of the Company's valuation allowance assessment.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Segment and Geographic Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
Segment and Geographic Information (Details) $ in Thousands	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| segment									1
Property and equipment, net	$ 1,478,272				$ 1,152,153				$ 1,478,272	$ 1,152,153
Operating lease right-of-use assets	793,945				758,450				793,945	758,450
Revenue	846,287	$ 792,845	$ 794,715	$ 764,302	772,123	$ 709,912	$ 705,074	$ 706,508	3,198,149	2,893,617	$ 2,714,474
U.S.
Segment Reporting Information [Line Items]
Property and equipment, net	572,400				482,700				572,400	482,700
Operating lease right-of-use assets	612,000				597,900				612,000	597,900
Revenue									1,777,435	1,694,211	1,683,272
Non-U.S.
Segment Reporting Information [Line Items]
Property and equipment, net	487,200				303,700				487,200	303,700
Operating lease right-of-use assets	$ 182,000				$ 160,600				182,000	160,600
Revenue									$ 1,420,700	$ 1,199,400	$ 1,031,200

- Definition

+ References

+ Details

Fair Value Measurements - Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,114,541	$ 1,961,972
Gross unrealized gains	9,824	1,943
Gross unrealized losses	(339)	(459)
Aggregate Fair Value	2,124,026	1,963,456
Short-term marketable securities	744,290	1,143,006
Long-term marketable securities	1,379,736	820,450
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		150,000
Gross unrealized gains		0
Gross unrealized losses		0
Aggregate Fair Value		150,000
Short-term marketable securities		150,000
Long-term marketable securities		0
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	46,931	73,829
Gross unrealized gains	13	23
Gross unrealized losses	(8)	(7)
Aggregate Fair Value	46,936	73,845
Short-term marketable securities	46,936	73,845
Long-term marketable securities	0	0
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,628,462	1,368,668
Gross unrealized gains	9,482	1,840
Gross unrealized losses	(262)	(378)
Aggregate Fair Value	1,637,682	1,370,130
Short-term marketable securities	607,403	753,538
Long-term marketable securities	1,030,279	616,592
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,495
Gross unrealized gains	0
Gross unrealized losses	(6)
Aggregate Fair Value	3,489
Short-term marketable securities	0
Long-term marketable securities	3,489
U.S. government agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	435,653	369,475
Gross unrealized gains	329	80
Gross unrealized losses	(63)	(74)
Aggregate Fair Value	435,919	369,481
Short-term marketable securities	89,951	165,623
Long-term marketable securities	$ 345,968	$ 203,858

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2020
Compensation Related Costs [Abstract]
Employee Benefit Plan	Employee Benefit PlanThe Company has established a savings plan for its employees that is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to this plan through payroll deductions within statutory and plan limits. The Company contributed approximately $17.5 million, $16.6 million and $16.7 million of cash to the savings plan for the years ended December 31, 2020, 2019 and 2018, respectively, under a matching program.

Income Taxes - Provision for Income Tax Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current tax (benefit) provision:
Federal	$ (1,765)	$ (22,704)	$ (29,982)
State	5,346	3,835	8,085
Foreign	76,162	71,286	64,274
Deferred tax (benefit) provision:
Federal	(19,845)	(13,987)	5,954
State	(14,509)	(12,212)	701
Foreign	(6,023)	4,968	(7,140)
Change in valuation allowance	6,556	22,164	2,824
Total	$ 45,922	$ 53,350	$ 44,716

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Tax expense on change in unrealized gain on investments	$ 2,720	$ 666	$ 200

Business Acquisitions (Tables)

12 Months Ended

Dec. 31, 2020

Business Combinations [Abstract]

Schedule of Purchase Price Allocation

The following table presents the preliminary allocation of the purchase price for Asavie (in thousands):


Total purchase consideration	$	154,952

Allocation of the purchase consideration:
Cash	$	26,847
Accounts receivable	14,002
Prepaid expenses and other current assets	995
Property and equipment	2,274
Operating lease right-of-use assets	6,104
Identifiable intangible assets	58,070
Goodwill	70,228
Other assets	395
Total assets acquired	178,915
Accounts payable	(951)
Accrued liabilities	(5,926)
Deferred revenue	(3,136)
Operating lease liabilities	(6,104)
Deferred income tax liabilities	(6,965)
Other liabilities	(881)
Total liabilities assumed	(23,963)
Net assets acquired	$	154,952

The following table presents the final allocation of the purchase price for Janrain (in thousands):


Total purchase consideration	$	123,632

Allocation of the purchase consideration:
Cash	$	2,223
Accounts receivable	7,318
Prepaid expenses and other current assets	838
Identifiable intangible assets	26,930
Goodwill	92,188
Deferred tax asset	12,622
Other assets	87
Total assets acquired	142,206
Accounts payable	(1,642)
Accrued liabilities	(2,596)
Deferred revenue	(14,336)

Total liabilities assumed	(18,574)
Net assets acquired	$	123,632

Schedule of Acquired Intangible Assets

Acquired intangible assets that are subject to amortization consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020						December 31, 2019
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Completed technologies	$	172,346	$	(111,435)	$	60,911	$	153,722	$	(94,088)	$	59,634
Customer-related intangible assets	358,032		(186,733)		171,299		279,684		(163,155)		116,529
Non-compete agreements	373		(77)		296		830		(529)		301
Trademarks and trade names	7,658		(5,440)		2,218		7,600		(4,633)		2,967
Acquired license rights	490		(490)		—		490		(490)		—
Total	$	538,899	$	(304,175)	$	234,724	$	442,326	$	(262,895)	$	179,431

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	17,300	10.1
Customer-related intangible assets	40,400		11.1
Trademarks	100		0.9
Non-compete agreements	270		2.9
Total	$	58,070

The following were the identified intangible assets acquired and their respective weighted average useful lives (in thousands, except years):


	Gross Carrying Amount		Weighted Average Useful Life (in years)
Completed technologies	$	9,000	7.9
Customer-related intangible assets	17,700		13.9
Trademarks	200		1.9
Non-compete agreements	30		1.9
Total	$	26,930

Segment and Geographic Information	12 Months Ended
Segment and Geographic Information	Dec. 31, 2020
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic InformationThe Company’s chief operating decision-maker is the chief executive officer and the executive management team. As of December 31, 2020, the Company operated in one industry segment: providing cloud services for securing, delivering and optimizing content and business applications over the internet. The Company is not organized by market and is managed and operated as one business. A single management team that reports to the chief executive officer comprehensively manages the entire business. The Company does not operate any material separate lines of business or separate business entities with respect to its services. Accordingly, the Company does not accumulate discrete financial information with respect to separate divisions and does not have separate operating or reportable segments. The Company deploys its servers into networks worldwide. As of December 31, 2020, the Company had approximately $572.4 million and $487.2 million of net property and equipment, excluding internal-use software, located in the U.S. and foreign locations, respectively. As of December 31, 2019, the Company had approximately $482.7 million and $303.7 million of net property and equipment, excluding internal-use software, located in the U.S. and foreign locations, respectively. As of December 31, 2020, the Company had approximately $612.0 million and $182.0 million of operating lease right-of-use assets located in the U.S. and foreign locations, respectively. As of December 31, 2019, the Company had approximately $597.9 million and $160.6 million of operating lease right-of-use assets located in the U.S. and foreign locations, respectively. The Company sells its services and licenses through a sales force located both domestically and abroad. Revenue derived from operations outside of the U.S. is determined based on the country in which the sale originated and was $1,420.7 million, $1,199.4 million and $1,031.2 million for the years ended December 31, 2020, 2019 and 2018, respectively. Other than the U.S., no single country accounted for 10% or more of the Company’s total revenue for any reported period.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8981-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 26
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8844-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8657-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-URI http://asc.fasb.org/topic&trid=2134510

+ Details

Akamai Foundation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Akamai Foundation (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2018
The Akamai Foundation \| One-Time Charitable Endowment
Related Party Transaction [Line Items]
Contribution amount	$ 20.0	$ 50.0

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 3,657,958	$ 3,191,860	$ 3,362,469
Other comprehensive income	24,943	3,768	(26,982)
Ending Balance	4,251,296	3,657,958	3,191,860
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(45,144)	(48,912)	(21,930)
Ending Balance	(20,201)	(45,144)	(48,912)
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(52,924)	(51,904)
Other comprehensive income	19,629	(1,020)
Ending Balance	(33,295)	(52,924)	(51,904)
Net Unrealized Gains on Investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	7,780	2,992
Other comprehensive income	5,314	4,788
Ending Balance	$ 13,094	$ 7,780	$ 2,992

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References + Details

Restructuring (Tables)

12 Months Ended

Dec. 31, 2020

Restructuring and Related Activities [Abstract]

Schedule of Restructuring Accrual

The following table summarizes the activity of the Company's restructuring accrual during the years ended December 31, 2020, 2019 and 2018 (in thousands):


	Employee Severance and Related Benefits		Software Charges		Other		Total
Balance January 1, 2018	$	12,857	$	—	$	1,386	$	14,243
Costs incurred	15,841		4,940		6,813		27,594
Cash disbursements	(18,922)		—		(5,932)		(24,854)
Software and other non-cash charges	—		(4,742)		(1,787)		(6,529)
Translation adjustments and other	732		—		(205)		527
Balance December 31, 2018	10,508		198		275		10,981
Costs incurred	12,455		3,784		914		17,153
Cash disbursements	(17,294)		(99)		(1,038)		(18,431)
Software and other non-cash charges	—		(3,784)		—		(3,784)
Translation adjustments and other	38		—		—		38
Balance December 31, 2019	5,707		99		151		5,957
Costs incurred	26,332		833		1,380		28,545
Cash disbursements	(10,118)		(99)		(1,531)		(11,748)
Software and other non-cash charges	—		(833)		—		(833)
Translation adjustments and other	130		—		—		130
Balance December 31, 2020	$	22,051	$	—	$	—	$	22,051

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Rent expense		$ 63.2
Sublease income		$ 3.8
Operating lease not yet commenced	$ 13.6
Future sublease income	216.7
Outstanding letter of credit	$ 5.8
Minimum
Lessee, Lease, Description [Line Items]
Term of operating lease not yet commenced	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of operating lease not yet commenced	7 years
Real Estate Arrangements
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	11 years 9 months 18 days		12 years 9 months 18 days
Weighted average discount rate	3.40%		3.50%
Co-location Arrangements
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (in years)	4 years 3 months 18 days		3 years 10 months 24 days
Weighted average discount rate	1.80%		2.20%

Income Taxes - Components of Income Tax Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S.	$ 45,074	$ 24,253	$ (27,379)
Foreign	571,008	508,228	370,468
Income before provision for income taxes	$ 616,082	$ 532,481	$ 343,089

Prepaid Expenses and Other Current Assets - Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid income taxes	$ 30,682	$ 26,143
Prepaid sales and other taxes	24,034	16,213
Prepaid equipment and software maintenance	15,526	18,114
Deferred commissions	54,516	45,009
Other prepaid expenses	26,187	19,593
Other current assets	20,461	17,604
Total	$ 171,406	$ 142,676

Income Taxes - Schedule of Difference Between Effective and Statutory (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal income tax rate	21.00%	21.00%	21.00%
State taxes	1.00%	1.00%	1.20%
Stock-based compensation	(0.60%)	0.30%	1.00%
U.S. federal, state and foreign research and development credits	(4.40%)	(6.00%)	(7.60%)
Foreign earnings	(7.70%)	(6.10%)	(6.00%)
Nondeductible (nontaxable) foreign items	(0.40%)	0.70%	0.40%
Impact of U.S. Tax Cuts and Jobs Act, net	0	0	(0.008)
Release of uncertain tax position reserve	(0.90%)	(5.90%)	(1.90%)
Intercompany sale of intellectual property	0.20%	1.90%	3.30%
Valuation allowance	1.10%	4.20%	0.80%
Other	(1.80%)	(1.10%)	1.60%
Effective income tax rate	7.50%	10.00%	13.00%

Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2020

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

Schedule of Accounts Receivable

Net accounts receivable consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Trade accounts receivable	$	473,474	$	396,204
Unbilled accounts receivable	188,400		157,619
Gross accounts receivable	661,874		553,823
Allowance for current expected credit losses and other reserves	(1,822)		(1,880)
Accounts receivable, net	$	660,052	$	551,943

Schedule of Activity in the Accounts Receivable Reserves

A summary of activity in the accounts receivable allowance for current expected credit losses and other reserves for the years ended December 31, 2020, 2019 and 2018 is as follows (in thousands):


	2020		2019		2018
Beginning balance	$	1,880	$	1,534	$	1,281
Charges to income from operations	12,347		5,116		3,824
Collections from customers previously reserved and other	(12,405)		(4,770)		(3,571)
Ending balance	$	1,822	$	1,880	$	1,534

Net Income per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Schedule of Components Used in Diluted and Basic Income Per Common Share

The following table sets forth the components used in the computation of basic and diluted net income per share for the years ended December 31, 2020, 2019 and 2018 (in thousands, except per share data):


	2020		2019		2018
Numerator:
Net income	$	557,054	$	478,035	$	298,373
Denominator:
Shares used for basic net income per share	162,490		162,706		167,312
Effect of dilutive securities:
Stock options	31		68		132
RSUs and DSUs	1,819		1,799		1,744
Convertible senior notes	873		—		—
Warrants related to issuance of convertible senior notes	—		—		—
Shares used for diluted net income per share	165,213		164,573		169,188
Basic net income per share	$	3.43	$	2.94	$	1.78
Diluted net income per share	$	3.37	$	2.90	$	1.76

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The number of potentially outstanding shares excluded from the computation of diluted net income per share for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020	2019	2018

Service-based RSUs	591	763	899
Market-and performance-based RSUs	1,409	1,349	1,509
Convertible senior notes	12,922	21,991	19,797
Warrants related to issuance of convertible senior notes	21,991	21,991	19,797
Total shares excluded from computation	36,913	46,094	42,002

Fair Value Measurements - Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 0	$ (6,300)
Cash paid upon achievement of milestone	0	6,300
Ending balance	$ 0	$ 0

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Deferred Tax	$ 23,170	$ 4,971
Issuance Costs	$ 2,880	$ 4,418

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2020

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of prepaid expense and other current assets

Prepaid expenses and other current assets consisted of the following as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Prepaid income taxes	$	30,682	$	26,143
Prepaid sales and other taxes	24,034		16,213
Prepaid equipment and software maintenance	15,526		18,114
Deferred commissions	54,516		45,009
Other prepaid expenses	26,187		19,593
Other current assets	20,461		17,604
Total	$	171,406	$	142,676

Schedule of deferred costs associated with obtaining customer contracts

The following table summarizes the deferred costs associated with obtaining customer contracts, specifically commission and incentive payments, as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Deferred costs included in prepaid and other current assets	$	54,516	$	45,009
Deferred costs included in other assets	23,200		25,698
Total deferred costs	$	77,716	$	70,707

Property and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, software and equipment depreciation, amortization expense	$ 436.3	$ 402.1	$ 401.2
Capitalization of stock-based compensation	38.0	35.9	$ 34.8
Disposal of property plant and equipment	279.9	166.7
Write off of internal-use software	$ 0.8	$ 3.8

Accounts Receivable - Activity in Allowance for Expected Credit Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,880	$ 1,534	$ 1,281
Charges to income from operations	12,347	5,116	3,824
Collections from customers previously reserved and other	(12,405)	(4,770)	(3,571)
Ending balance	$ 1,822	$ 1,880	$ 1,534

Net Income per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Net Income per Share

Net Income per ShareBasic net income per share is computed using the weighted average number of common shares outstanding during the applicable period. Diluted net income per share is computed using the weighted average number of common shares outstanding during the period, plus the dilutive effect of potential common stock. Potential common stock consists of shares issuable pursuant to stock options, RSUs, DSUs, convertible senior notes and warrants issued by the Company. The dilutive effect of outstanding awards and convertible securities is reflected in diluted earnings per share by application of the treasury stock method.


	2020		2019		2018
Numerator:
Net income	$	557,054	$	478,035	$	298,373
Denominator:
Shares used for basic net income per share	162,490		162,706		167,312
Effect of dilutive securities:
Stock options	31		68		132
RSUs and DSUs	1,819		1,799		1,744
Convertible senior notes	873		—		—
Warrants related to issuance of convertible senior notes	—		—		—
Shares used for diluted net income per share	165,213		164,573		169,188
Basic net income per share	$	3.43	$	2.94	$	1.78
Diluted net income per share	$	3.37	$	2.90	$	1.76

For the years ended December 31, 2020, 2019 and 2018, certain potential outstanding shares from stock options, service-based RSUs, convertible notes and warrants were excluded from the computation of diluted net income per share because the effect of including these items was anti-dilutive. Additionally, certain performance-based RSUs were excluded from the computation of diluted net income per share because the underlying performance conditions for such RSUs had not been met as of these dates. The number of potentially outstanding shares excluded from the computation of diluted net income per share for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020	2019	2018

Service-based RSUs	591	763	899
Market-and performance-based RSUs	1,409	1,349	1,509
Convertible senior notes	12,922	21,991	19,797
Warrants related to issuance of convertible senior notes	21,991	21,991	19,797
Total shares excluded from computation	36,913	46,094	42,002

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The Company prepares its consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. These principles require management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, and the amounts disclosed in the related notes to the consolidated financial statements. Actual results and outcomes may differ materially from management’s estimates, judgments and assumptions. Significant estimates, judgments and assumptions used in these financial statements include, but are not limited to, those related to revenue, accounts receivable and related reserves, valuation and impairment of investments and marketable securities, valuation and useful lives of acquired intangible assets, useful lives and realizability of long-lived assets, capitalized internal-use software development costs, income tax reserves and accounting for stock-based compensation. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. The effects of material revisions in estimates are reflected in the consolidated financial statements prospectively from the date of the change in estimate. Cash, Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash held in bank deposit accounts and short-term, highly-liquid investments with remaining maturities of three months or less at the date of purchase. Marketable securities consist of corporate, government and other securities. Securities having remaining maturities of less than one year from the date of the balance sheet are classified as short-term, and those with maturities of more than one year from the date of the balance sheet are classified as long-term in the consolidated balance sheets. The Company classifies its debt securities with readily determinable market values as available-for-sale. These investments are classified as marketable securities on the consolidated balance sheets and are carried at fair market value, with unrealized gains and losses considered to be temporary in nature and reported as accumulated other comprehensive loss, a separate component of stockholders’ equity. The Company reviews all investments for reductions in fair value that are other-than-temporary. When such reductions occur, the cost of the investment is adjusted to fair value through recording a loss on investments in the consolidated statements of income. Gains and losses on investments are calculated on the basis of specific identification. Marketable securities are considered to be impaired when a decline in fair value below cost basis is determined to be other-than-temporary. The Company periodically evaluates whether a decline in fair value below cost basis is other-than-temporary by considering available evidence regarding these investments including, among other factors: the duration of the period that, and extent to which, the fair value is less than cost basis; the financial health and business outlook of the issuer, including industry and sector performance and operational and financing cash flow factors; overall market conditions and trends; and the Company’s intent and ability to retain its investment in the security for a period of time sufficient to allow for an anticipated recovery in market value. Once a decline in fair value is determined to be other-than-temporary, a write-down is recorded and a new cost basis in the security is established. Assessing the above factors involves inherent uncertainty. Write-downs, if recorded, could be materially different from the actual market performance of marketable securities in the Company’s portfolio if, among other things, relevant information related to the marketable securities was not publicly available or other factors not considered by the Company would have been relevant to the determination of impairment. Accounts Receivable and Related Reserves The Company’s accounts receivable balance includes unbilled amounts that represent revenue recorded for customers that are typically billed monthly in arrears. The Company records reserves against its accounts receivable balance which primarily consists of allowances for current expected credit losses. Increases and decreases in the allowance for current expected credit losses are included as a component of general and administrative expense in the consolidated statements of income. The allowance for current expected credit losses has been developed using historical loss rates for the previous twelve months as well as expectations about the future where the Company has been able to develop forecasts to support its estimates. In addition, the allowance considers outstanding balances on a customer-specific, account-by-account basis. The Company assesses collectibility based upon a review of customer receivables from prior sales with collection issues where the Company no longer believes that the customer has the ability to pay for services previously provided. The Company also performs ongoing credit evaluations of its customers. If such an evaluation indicates that payment is no longer reasonably assured for services provided, any future services provided to that customer will result in the creation of a cash-basis reserve until the Company receives consistent payments. The Company does not have any off-balance sheet credit exposure related to its customers. Incremental Costs to Obtain a Contract with a Customer The Company capitalizes incremental costs associated with obtaining customer contracts, specifically certain commission and incentive payments. The Company pays commissions and incentives up-front based on contract value upon signing a new arrangement with a customer and upon renewal and upgrades of existing contracts with customers if the renewal and upgrades result in an incremental increase in contract value. To the extent commissions and incentives are earned, the expenses, including estimated payroll taxes, are deferred on the Company's consolidated balance sheet and amortized over the expected life of the customer arrangement on a straight-line basis. Based on the nature of the Company's unique technology and services, and the rate at which the Company continually enhances and updates its technology, the expected life of the customer arrangement is determined to be approximately 2.5 years. Additionally, the Company may pay commissions and incentives based upon contract value, rather than incremental increase in contract value, to certain sales groups within the Company. For these commission arrangements, the Company amortizes capitalized costs for contract renewals over an average renewal contract period of 16 months. The Company also incurs commission expense on an ongoing basis based upon revenue recognized. In these cases, no incremental costs are deferred, as the commissions are earned and expensed in the same period for which the associated revenue is recognized. Amortization of the costs is primarily included in sales and marketing expense in the consolidated statements of income. The current portion of deferred commission and incentive payments is included in prepaid expenses and other current assets, and the long-term portion is included in other assets on the Company's consolidated balance sheets. Concentrations of Credit Risk The amounts reflected in the consolidated balance sheets for accounts receivable, other current assets, accounts payable, accrued liabilities and other current liabilities approximate fair values due to their short-term maturities. The Company maintains the majority of its cash, cash equivalents and marketable securities with major financial institutions that the Company believes to be of high credit standing. The Company believes that, as of December 31, 2020, its concentration of credit risk related to cash equivalents and marketable securities was not significant. Concentrations of credit risk with respect to accounts receivable are primarily limited to certain customers to which the Company makes substantial sales. The Company’s customer base consists of a large number of geographically-dispersed customers diversified across several industries. To reduce risk, the Company routinely assesses the financial strength of its customers. Based on such assessments, the Company believes that its accounts receivable credit risk exposure is limited. For the years ended December 31, 2020, 2019 and 2018, no customer accounted for more than 10% of total revenue. As of December 31, 2020 and 2019, no customer had an accounts receivable balance greater than 10% of total accounts receivable. The Company believes that, as of December 31, 2020, its concentration of credit risk related to accounts receivable was not significant. Fair Value of Financial Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company has certain financial assets and liabilities recorded at fair value, principally cash equivalents and short- and long-term marketable securities that have been classified as Level 1, 2 or 3 within the fair value hierarchy. Fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company can access at the reporting date. Fair values determined by Level 2 inputs utilize data points other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Fair values determined by Level 3 inputs are based on unobservable data points for the asset or liability. Property and Equipment Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Property and equipment generally include purchases of items with a per-unit value greater than $1,000 and an estimated useful life greater than one year. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the related lease terms or their estimated useful lives. The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in income from operations. Repairs and maintenance costs are expensed as incurred. The Company has implemented software and hardware initiatives to manage its global network more efficiently and, as a result, the expected average useful life of its network assets, primarily servers, increased from four years to five years, effective January 1, 2019. These changes decreased depreciation expense by $22.9 million and increased net income by $19.2 million, or $0.12 per share, for the year ended December 31, 2020 and decreased depreciation expense by $31.5 million and increased net income by $26.1 million, or $0.16 per share, for the year ended December 31, 2019. Operating Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued guidance that requires companies to present assets and liabilities arising from leases on the consolidated balance sheet. The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize right of use ("ROU") assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The Company adopted this standard on January 1, 2019 on a modified retrospective basis by applying the new standard to its lease portfolio as of January 1, 2019, while continuing to apply legacy guidance in the comparative periods. The Company enters into operating leases for real estate assets related to office space and co-location assets related to space or racks at co-location facilities and related equipment for its servers and other networking equipment. The Company determines if an arrangement contains a lease at the inception of a contract by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration and the right to obtain the economic benefits from the use of the identified asset. Upon commencement of a lease, the Company records a right-of-use asset that represents the Company’s right to use the underlying asset for the lease term and a lease liability that represents an obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. Lease payments are discounted at the lease commencement date. As the Company’s leases do not provide an implicit rate, an incremental borrowing rate has been applied based on the Company's credit-adjusted risk-free rate. The Company often enters into contracts that contain both lease and non-lease components. Real estate non-lease components include real estate taxes, insurance, maintenance, parking and other operating costs. Co-location non-lease components include utilities and other operating costs. The Company includes both lease and non-lease components of fixed costs in its lease arrangements as a single lease component. Variable costs, such as utilities based on actual usage, are not included in the measurement of right-of-use assets and lease liabilities but are expensed when the event determining the amount of variable consideration to be paid occurs. The Company’s lease terms often include renewal options and, particularly in the case of co-location arrangements, may include evergreen provisions. The Company’s right-of-use assets and lease liabilities generally do not include the options to extend, or terminate, unless it is reasonably certain that the Company will exercise these options. The Company has elected to exclude leases for certain networking equipment with terms of 12 months or less from its right-of-use assets and lease liabilities on its consolidated balance sheet. Lease expense is recognized on a straight-line basis over the expected lease term. Equity Method Investments The Company accounts for equity investments in which it has significant influence, but not a controlling financial interest, using the equity method of accounting. Under the equity method of accounting, investments are initially recorded at cost, less impairment, and subsequently adjusted to recognize the Company’s share of earnings or losses. In February 2019, the Company and Mitsubishi UFJ Financial Group ("MUFG") announced the establishment of a joint venture, the Global Open Network, Inc. ("GO-NET"), and their plans to offer a new blockchain-based online payment network. The Company's 20% stake in GO-NET is accounted for using the equity method. As of December 31, 2020, the Company's $21.6 million investment is included in other assets on the consolidated balance sheet. The Company recorded a loss of $13.1 million during the year ended December 31, 2020, comprised of $2.1 million to record its share of operating losses incurred by GO-NET during the year and an $11.0 million impairment to reduce the Company's investment to its fair value due to a modified business plan and continued negative projected cash flows. The valuation technique used to measure fair value of the Company's equity method investment in GO-NET was primarily an adjusted net asset value model based on labor costs and the amount of time required to develop a similar technology for use in the planned payment processing service. The Company recorded a loss of $1.1 million during the year ended December 31, 2019, which reflects its share of the losses incurred by GO-NET during the year. Subsequent to the establishment of the joint venture, the Company recorded revenue of $11.1 million and $11.6 million for the years ended December 31, 2020 and 2019, respectively, for services provided to GO-NET. Goodwill, Acquired Intangible Assets and Long-Lived Assets Goodwill is the amount by which the cost of acquired net assets in a business combination exceeds the fair value of the net identifiable assets on the date of purchase and is carried at its historical cost. The Company tests goodwill for impairment on an annual basis or more frequently if events or changes in circumstances indicate that the asset might be impaired. The Company performs its impairment test of goodwill as of December 31 each year. As of December 31, 2020, 2019 and 2018, the fair value of the Company's reporting unit was substantially in excess of the carrying value. The tests did not result in an impairment to goodwill during the years ended December 31, 2020, 2019 and 2018. Acquired intangible assets consist of completed technologies, customer relationships, trademarks and trade names, non-compete agreements and acquired license rights. Acquired intangible assets, other than goodwill, are amortized over their estimated useful lives based upon the estimated economic value derived from the related intangible asset. Long-lived assets, including property and equipment and acquired intangible assets, are reviewed for impairment whenever events or changes in circumstances, such as service discontinuance, technological obsolescence, significant decreases in the Company’s market capitalization, facility closures or work-force reductions indicate that the carrying amount of the long-lived asset may not be recoverable. When such events occur, the Company compares the carrying amount of the asset to the undiscounted expected future cash flows related to the asset. If this comparison indicates that an impairment is present, the amount of the impairment is calculated as the difference between the carrying amount and the fair value of the asset. Contract Liabilities Contract liabilities primarily represent payments received from customers for which the related performance obligations have not yet been satisfied. These balances consist of the unearned portion of monthly service fees and integration fees and prepayments made by customers for future periods. The current and long-term portions of the Company's contract liabilities are included in deferred revenue in the respective sections of the Company's consolidated balance sheets. Revenue Recognition The Company primarily derives revenue from the sale of services to customers executing contracts having terms of one year or longer. Services included in the Company's contracts consist of its core services – the delivery of content, applications and software over the internet – as well as security solutions and professional services. Revenue is recognized upon transfer of control of promised services in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company enters into contracts that may include various combinations of these services, which are generally capable of being distinct and accounted for as separate performance obligations. These contracts generally commit the customer to a minimum of monthly, quarterly or annual levels of usage and specify the rate at which the customer must pay for actual usage above the stated minimum. Based on the typical structure of the Company's contracts, which are generally for monthly recurring services that are essentially the same over time and have the same pattern of transfer to the customer, most performance obligations represent a promise to deliver a series of distinct services over time. The Company's contracts with customers sometimes include promises to deliver multiple services to a customer. Determining whether services are distinct performance obligations often requires the exercise of judgment by management. For example, advanced features that enhance a service and are highly interrelated are generally not considered distinct; rather, they are combined with the service they relate to into one performance obligation. Different determinations related to combining services into performance obligations could result in differences in the timing and amount of revenue recognized in a period. Generally, the transaction price in a contract is equal to the committed price stated in the contract, less any discounts or rebates. The Company's typical contracts qualify for series accounting, and the pricing terms generally do not require estimation of the transaction price beyond the reporting period. As a result, any incremental fees generated as a result of usage or “bursting” over committed contract levels are recorded in the period to which the services relate. The amount of consideration recognized for usage above contract minimums is limited to the amount the Company expects to be entitled to receive in exchange for providing the services. Once the transaction price has been determined, the Company allocates such price among all performance obligations in the contract on a relative standalone selling price (“SSP”) basis. Determination of SSP requires the exercise of judgment by management. SSP is based on observable inputs such as the price the Company charges for the service when sold separately or the discounted list price per management’s approved price list. In cases where services are not sold separately or price list rates are not available, a cost-plus-margin approach or adjusted market approach is used to determine SSP. Most content delivery and security services represent stand-ready obligations that are satisfied over time as the customer simultaneously receives and consumes the benefits provided by the Company. Accordingly, revenue for those services is recognized over time, generally ratably over the term of the arrangement due to consistent monthly traffic commitments that expire each period. Any bursting over given commitments is recognized in the period in which the traffic was served. For services that involve traffic consumption, revenue is recognized in an amount that reflects the level of traffic served to a customer in a given period. For custom arrangements, other methods may be used as a measure of progress towards satisfying the performance obligations. Some of the Company's services are satisfied at a point in time, such as one-time professional services contracts, integration services and most license sales where the primary obligation is delivery of the license at the start of the term. In these cases, revenue is recognized at the point in time of delivery or satisfaction of the performance obligation. From time to time, the Company enters into contracts to sell its services or license its technology to unrelated enterprises at or about the same time that it enters into contracts to purchase products or services from the same enterprises. Consideration payable to a customer is reviewed as part of the transaction price. If the payment to the customer does not represent payment for a distinct service, revenue is recognized only up to the net amount of consideration after customer payment obligations are considered. The Company may also resell the licenses or services of third parties. If the Company is acting as an agent in an arrangement with a customer to provide third party services, the transaction price reflects only the net amount to which the Company will be entitled, after accounting for payments made to the third party responsible for satisfying the performance obligation. Cost of Revenue Cost of revenue consists primarily of fees paid to network providers for bandwidth and to third-party network data centers for housing servers, also known as co-location costs. Cost of revenue also includes employee costs for services delivery and network operation, build-out and support of the Company's network; network storage costs; cost of software licenses; depreciation of network equipment used to deliver the Company’s services; amortization of network-related internal-use software; and costs for the production of live events streamed by the Company for customers. The Company enters into contracts for bandwidth with third-party network providers with terms typically ranging from several months to five years. These contracts generally commit the Company to pay minimum monthly fees plus additional fees for bandwidth usage above the committed level. In some circumstances, internet service providers (“ISPs”) make rack space available for the Company to locate its servers and provide access to their bandwidth at a discount or no cost. Although the Company does not provide any goods or services to the ISPs or the ISPs’ customers under these arrangements, the ISPs and their customers indirectly benefit by accessing content through a local Company server, resulting in better content delivery. The Company records the cost of these vendor relationships at their negotiated transaction price, which is either at a discount or no cost. Research and Development Costs and Capitalized Internal-Use Software Research and development costs consist primarily of payroll and related personnel costs for the design, development, deployment, testing and enhancement of the Company’s services and network. Costs incurred in the development of the Company’s services are expensed as incurred, except certain internal-use software development costs eligible for capitalization. Capitalized costs include external consulting fees, payroll and payroll-related costs and stock-based compensation for employees in the Company’s development and information technology groups who are directly associated with, and who devote time to, the Company’s internal-use software projects. Capitalization begins when the planning stage is complete and the Company commits resources to the software project; capitalization continues during the application development stage. Capitalization ceases when the software has been tested and is ready for its intended use. Costs incurred during the planning, training and post-implementation stages of the software development life-cycle are expensed as incurred. The Company amortizes completed internal-use software that is used on its network to cost of revenue over its estimated useful life. Accounting for Stock-Based Compensation The Company recognizes compensation costs for all stock-based payment awards made to employees based upon the awards’ grant-date fair value. The stock-based payment awards include stock options, restricted stock units, deferred stock units and employee stock purchases related to the Company’s employee stock purchase plan. For stock options, the Company has selected the Black-Scholes option-pricing model to determine the fair value of stock option awards. For stock awards with market-based vesting conditions, the Company uses a Monte Carlo simulation to determine the fair value of the award. For stock options, restricted stock units and deferred stock units that contain only a service-based vesting feature, the Company recognizes compensation cost on a straight-line basis over the award's vesting period. For awards with a performance condition-based vesting feature, the Company recognizes compensation cost on a graded-vesting basis over the award's expected vesting period, commencing when achievement of the performance condition is deemed probable. In addition, for awards that vest and become exercisable only upon achievement of specified performance conditions, the Company makes judgments and estimates each quarter about the probability that such performance conditions will be met or achieved. Any changes to those estimates that the Company makes from time to time may have a significant impact on the stock-based compensation expense recorded and could materially impact the Company’s results of operations. Foreign Currency Translation and Forward Currency Contracts The assets and liabilities of the Company's subsidiaries are translated at the applicable exchange rate as of the balance sheet date, and revenue and expenses are translated at an average rate over the period. Resulting currency translation adjustments are recorded as a component of accumulated other comprehensive loss, a separate component of stockholders’ equity. Gains and losses on inter-company and other non-functional currency transactions are recorded in other expense, net. The Company enters into short-term foreign currency forward contracts to offset foreign exchange gains and losses generated by the re-measurement of certain assets and liabilities recorded in non-functional currencies. Changes in the fair value of these derivatives, as well as re-measurement gains and losses, are recognized in current earnings in other expense, net. As of December 31, 2020 and 2019, the fair value of the forward currency contracts and the underlying net gains for the years ended December 31, 2020, 2019 and 2018 were immaterial. The Company's foreign currency forward contracts may be exposed to credit risk to the extent that its counterparties are unable to meet the terms of the agreements. The Company seeks to minimize counterparty credit (or repayment) risk by entering into transactions only with major financial institutions of investment grade credit rating. Income Taxes The Company's provision for income taxes is comprised of a current and a deferred portion. The current income tax provision is calculated as the estimated taxes payable or refundable on tax returns for the current year. The deferred income tax provision is calculated as the estimated future tax effects attributable to temporary differences and carryforwards using expected tax rates in effect in the years during which the differences are expected to reverse or the carryforwards are expected to be realized. The Company currently has net deferred tax assets consisting of net operating loss (“NOL”) carryforwards, tax credit carryforwards and deductible temporary differences. Management periodically weighs the positive and negative evidence to determine if it is more-likely-than-not that some or all of the deferred tax assets will be realized. The Company has recorded certain tax reserves to address potential exposures involving its income tax positions. These potential tax liabilities result from the varying application of statutes, rules, regulations and interpretations by different taxing jurisdictions. The Company's estimate of the value of its tax reserves contains assumptions based on past experiences and judgments about the interpretation of statutes, rules and regulations by taxing jurisdictions. It is possible that the costs of the ultimate tax liability or benefit from these matters may be more or less than the amount the Company estimated. Uncertainty in income taxes is recognized in the Company's consolidated financial statements using a two-step process. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination. If the tax position is deemed more-likely-than-not to be sustained based on technical merit, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. Newly-Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board ("FASB") issued guidance that introduces a new methodology for accounting for credit losses on financial instruments. The guidance establishes a new "expected credit loss model" that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Any expected credit losses are to be reflected as allowances. The Company prospectively adopted this standard on January 1, 2020. Adoption of the standard did not have a material impact on the Company's consolidated financial statements. In August 2018, the FASB issued guidance that addresses a customer’s accounting for implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance aligns the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement with the guidance for capitalizing costs associated with developing or obtaining internal-use software. The Company prospectively adopted this standard on January 1, 2020. Adoption of the standard did not have a material impact on the Company's consolidated financial statements. Recent Accounting Pronouncements In August 2020, the FASB issued guidance that is expected to reduce complexity and improve comparability of financial reporting associated with accounting for convertible instruments and contracts in an entity’s own equity. This guidance will be effective for the Company on January 1, 2022. The Company is evaluating the potential impact of adopting this new accounting guidance on its consolidated financial statements related to the accounting for convertible debt arrangements.

Debt (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Schedule of Convertible Senior Notes

The 2027 Notes consisted of the following components as of December 31, 2020 and 2019 (in thousands):


	December 31, 2020		December 31, 2019
Liability component:
Principal	$	1,150,000	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(196,359)		(222,928)
Net carrying amount	$	953,641	$	927,072

Equity component:	$	220,529	$	220,529

The 2025 Notes consist of the following components as of December 31, 2020 and December 31, 2019 (in thousands):


	December 31, 2020		December 31, 2019
Liability component:
Principal	$	1,150,000	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(196,934)		(237,281)
Net carrying amount	$	953,066	$	912,719

Equity component:	$	285,225	$	285,225

Schedule of Interest Expense

The following table sets forth total interest expense included in the consolidated statements of income for the years ended December 31, 2020, 2019 and 2018 (in thousands):


	2020		2019		2018
Amortization of debt discount and issuance costs	$	67,153	$	52,059	$	46,493
Coupon interest payable on 2025 Notes	1,437		1,436		874
Coupon interest payable on 2027 Notes	4,312		1,557		—
Revolving credit facility contractual interest expense	548		513		368
Capitalization of interest expense	(4,330)		(6,201)		(4,533)
Total interest expense	$	69,120	$	49,364	$	43,202

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Stock-Based Compensation - Schedule of Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months	6 months
Risk-free interest rate	0.70%	2.30%	1.90%
Expected volatility	30.40%	29.60%	31.20%
Dividend yield	0.00%	0.00%	0.00%
Market-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	3 years	3 years	3 years
Risk-free interest rate	0.70%	2.50%	2.30%
Expected volatility	28.20%	32.80%	35.50%
Average volatility of peer-company share price	28.90%	27.00%	26.30%

Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
Restructuring (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 37,286	$ 17,153	$ 27,594
Restructuring Reserve [Roll Forward]
Balance	5,957	10,981	14,243
Costs incurred	28,545	17,153	27,594
Cash disbursements	(11,748)	(18,431)	(24,854)
Software and other non-cash charges	(833)	(3,784)	(6,529)
Translation adjustments and other	130	38	527
Balance	22,051	5,957	10,981
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Balance	5,707	10,508	12,857
Costs incurred	26,332	12,455	15,841
Cash disbursements	(10,118)	(17,294)	(18,922)
Software and other non-cash charges	0	0	0
Translation adjustments and other	130	38	732
Balance	22,051	5,707	10,508
Software Charges
Restructuring Reserve [Roll Forward]
Balance	99	198	0
Costs incurred	833	3,784	4,940
Cash disbursements	(99)	(99)	0
Software and other non-cash charges	(833)	(3,784)	(4,742)
Translation adjustments and other	0	0	0
Balance	0	99	198
Other
Restructuring Reserve [Roll Forward]
Balance	151	275	1,386
Costs incurred	1,380	914	6,813
Cash disbursements	(1,531)	(1,038)	(5,932)
Software and other non-cash charges	0	0	(1,787)
Translation adjustments and other	0	0	(205)
Balance	0	151	275
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charge	23,600
2020 Restructuring Plan \| Employee Severance and Related Benefits
Restructuring Cost and Reserve [Line Items]
Expected restructuring charge	7,000
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date	23,400
Restructuring charge	13,200	$ 10,200
Impairment loss on right-of-use asset	8,700
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date	19,000
Restructuring charge	$ 6,700		$ 12,300

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
Employee Benefit Plan (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation Related Costs [Abstract]
Contributions by employer	$ 17.5	$ 16.6	$ 16.7

- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References + Details

Goodwill and Acquired Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Changes in the carrying amount of goodwill
Beginning balance	$ 1,600,265	$ 1,487,404
Measurement period adjustments related to acquisitions completed in prior years	(1,056)	0
Foreign currency translation	4,962	(1,108)
Ending balance	1,674,371	1,600,265
Janrain, Inc.
Changes in the carrying amount of goodwill
Acquisition	0	92,188
Exceda
Changes in the carrying amount of goodwill
Acquisition	0	14,712
ChameleonX
Changes in the carrying amount of goodwill
Acquisition	0	7,069
Asavie
Changes in the carrying amount of goodwill
Acquisition	$ 70,200	$ 0