Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning balance (in shares) at Dec. 31, 2019		189,461
Beginning balance at Dec. 31, 2019	$ 2,128,000	$ 0	$ 2,455,000	$ (352,000)	$ 25,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee stock plans (in shares)	3,300	3,304
Common stock issued under employee stock plans	$ 149,000		149,000
Taxes paid related to net share settlement of equity awards	(361,000)		(361,000)
Stock-based compensation	626,000		626,000
Settlement of 2022 Warrants (in shares)		2,285
Settlement of 2022 Warrants	0
Settlement of 2022 Notes conversion feature	(1,181,000)		(1,181,000)
Benefit from exercise of 2022 Note Hedge	1,184,000		1,184,000
Other comprehensive income (loss), net of tax	27,000				27,000
Net income	101,855			102,000
Ending balance (in shares) at Sep. 30, 2020		195,050
Ending balance at Sep. 30, 2020	2,674,000	$ 0	2,872,000	(250,000)	52,000
Beginning balance (in shares) at Jun. 30, 2020		191,801
Beginning balance at Jun. 30, 2020	2,479,000	$ 0	2,712,000	(263,000)	30,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee stock plans (in shares)		964
Common stock issued under employee stock plans	58,000		58,000
Taxes paid related to net share settlement of equity awards	(122,000)		(122,000)
Stock-based compensation	220,000		220,000
Settlement of 2022 Warrants (in shares)		2,285
Settlement of 2022 Notes conversion feature	(1,158,000)		(1,158,000)
Benefit from exercise of 2022 Note Hedge	1,162,000		1,162,000
Other comprehensive income (loss), net of tax	22,000				22,000
Net income	12,858			13,000
Ending balance (in shares) at Sep. 30, 2020		195,050
Ending balance at Sep. 30, 2020	2,674,000	$ 0	2,872,000	(250,000)	52,000
Beginning balance (in shares) at Dec. 31, 2020		195,845
Beginning balance at Dec. 31, 2020	$ 2,834,000	$ 0	2,974,000	(234,000)	94,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee stock plans (in shares)	2,600	2,614
Common stock issued under employee stock plans	$ 166,000		166,000
Taxes paid related to net share settlement of equity awards	(457,000)		(457,000)
Stock-based compensation	828,000		828,000
Shares granted related to business combination	6,000		6,000
Settlement of 2022 Warrants (in shares)		536
Settlement of 2022 Warrants	0
Settlement of 2022 Notes conversion feature	(216,000)		(216,000)
Benefit from exercise of 2022 Note Hedge	215,000		215,000
Other comprehensive income (loss), net of tax	(46,000)				(46,000)
Net income	203,725			204,000
Ending balance (in shares) at Sep. 30, 2021		198,995
Ending balance at Sep. 30, 2021	3,534,000	$ 0	3,516,000	(30,000)	48,000
Beginning balance (in shares) at Jun. 30, 2021		198,135
Beginning balance at Jun. 30, 2021	3,275,000	$ 0	3,298,000	(93,000)	70,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee stock plans (in shares)		860
Common stock issued under employee stock plans	71,000		71,000
Taxes paid related to net share settlement of equity awards	(142,000)		(142,000)
Stock-based compensation	290,000		290,000
Settlement of 2022 Warrants (in shares)		0
Settlement of 2022 Notes conversion feature	(25,000)		(25,000)
Benefit from exercise of 2022 Note Hedge	24,000		24,000
Other comprehensive income (loss), net of tax	(22,000)				(22,000)
Net income	62,890			63,000
Ending balance (in shares) at Sep. 30, 2021		198,995
Ending balance at Sep. 30, 2021	$ 3,534,000	$ 0	$ 3,516,000	$ (30,000)	$ 48,000