Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjustment	[2]	Common Stock		Additional Paid-in Capital	[1]	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	[2]	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2018	[1]				302,672
Beginning balance at Dec. 31, 2018		$ 2,143,389	$ 3,702		$ 30	[1]	$ 956,550		$ 1,190,803	$ 3,702		$ (3,994)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		859,867							859,867
Other comprehensive income (loss), net of tax		4,137										4,137
Stock-based compensation		101,280					101,280
Issuance of common stock in connection with employee equity incentive plans (in shares)	[1]				7,804
Issuance of common stock in connection with employee equity incentive plans		57,377					57,377
Repurchase of common stock (in shares)	[1]				(4,756)
Repurchase of common stock		(266,142)							(266,142)
Tax withholding paid for net share settlement of equity awards (in shares)	[1]				(164)
Tax withholding paid for net share settlement of equity awards		(9,200)					(9,200)
Vesting of early-exercised stock options		276					276
Ending balance (in shares) at Dec. 31, 2019	[1]				305,556
Ending balance at Dec. 31, 2019		2,894,686			$ 30	[1]	1,106,283		1,788,230			143
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		634,557							634,557
Other comprehensive income (loss), net of tax		95										95
Stock-based compensation		137,128					137,128
Issuance of common stock in connection with employee equity incentive plans (in shares)	[1]				7,336
Issuance of common stock in connection with employee equity incentive plans		$ 57,556					57,556
Repurchase of common stock (in shares)		(8,048)			(8,048)	[1]
Repurchase of common stock		$ (395,173)							(395,173)
Tax withholding paid for net share settlement of equity awards (in shares)	[1]				(148)
Tax withholding paid for net share settlement of equity awards		(8,722)					(8,722)
Vesting of early-exercised stock options		164					164
Ending balance (in shares) at Dec. 31, 2020	[1]				304,696
Ending balance at Dec. 31, 2020		3,320,291			$ 30	[1]	1,292,409		2,027,614			238
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		840,854							840,854
Other comprehensive income (loss), net of tax		(8,538)										(8,538)
Stock-based compensation		186,875					186,875
Issuance of common stock in connection with employee equity incentive plans (in shares)	[1]				7,693
Issuance of common stock in connection with employee equity incentive plans		$ 67,245			$ 1	[1]	67,244
Repurchase of common stock (in shares)		(4,537)			(4,537)	[1]
Repurchase of common stock		$ (411,645)							(411,645)
Tax withholding paid for net share settlement of equity awards (in shares)	[1]				(171)
Tax withholding paid for net share settlement of equity awards		(16,482)					(16,482)
Ending balance (in shares) at Dec. 31, 2021	[1]				307,681
Ending balance at Dec. 31, 2021		$ 3,978,600			$ 31	[1]	$ 1,530,046		$ 2,456,823			$ (8,300)

[1] Prior period results have been adjusted to reflect the four-for-one stock split effected in the form of a stock dividend in November 2021. See Note 1, Organization and Summary of Accounting Policies, for details.

[2] On January 1, 2019, we adopted ASC 842 - Leases, which resulted in a cumulative-effect adjustment to the beginning balance of Retained Earnings for 2019.