Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Beginning balance (in shares) at Dec. 31, 2016		115,973,039
Beginning balance at Dec. 31, 2016	$ 344,757	$ 116	$ 442,510	$ (116,341)	$ 18,472
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 26,594		26,594
Exercise of vested options (in shares)	5,760,263	5,760,263
Exercise of vested options	$ 33,838	$ 6	33,832
Vesting of restricted stock units, net of shares withheld (in shares)		622,167
Vesting of restricted stock units, net of shares withheld	$ (6,417)	$ 1	(6,418)
Stock repurchase (in shares)	(586,231)	(586,231)
Stock repurchase	$ (10,301)	$ (1)		(10,300)
Conversion of liability-classified restricted shares upon vesting	2,838		2,838
Other comprehensive loss	(24,851)				(24,851)
Net income	81,800			81,800
Ending balance (in shares) at Dec. 31, 2017		121,769,238
Ending balance at Dec. 31, 2017	396,894	$ 122	499,441	(96,290)	(6,379)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 40,483		40,483
Exercise of vested options (in shares)	1,588,779	1,588,779
Exercise of vested options	$ 18,253	$ 1	18,252
Issuance of convertible senior notes, net of issuance costs and taxes	53,323		53,323
Purchase of capped call, net of taxes	(25,400)		(25,400)
Vesting of restricted stock units, net of shares withheld (in shares)		860,102
Vesting of restricted stock units, net of shares withheld	$ (24,065)	$ 1	(24,066)
Stock repurchase (in shares)	(5,032,648)	(4,446,417)
Stock repurchase	$ (134,647)	$ (4)		(134,643)
Other comprehensive loss	(1,434)				(1,434)
Net income	$ 77,491			77,491
Ending balance (in shares) at Dec. 31, 2018	119,771,702	119,771,702
Ending balance at Dec. 31, 2018	$ 400,898	$ 120	562,033	(153,442)	(7,813)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 45,697		45,697
Exercise of vested options (in shares)	840,835	840,835
Exercise of vested options	$ 9,791	$ 1	9,790
Issuance of convertible senior notes, net of issuance costs and taxes	115,980		115,980
Purchase of capped call, net of taxes	(58,324)		(58,324)
Vesting of restricted stock units, net of shares withheld (in shares)		832,642
Vesting of restricted stock units, net of shares withheld	$ (32,547)	$ 1	(32,548)
Stock repurchase (in shares)	(6,040,859)	(3,102,407)
Stock repurchase	$ (176,985)	$ (3)		(176,982)
Other comprehensive loss	(886)				(886)
Net income	$ 95,894			95,894
Ending balance (in shares) at Dec. 31, 2019	118,342,772	118,342,772
Ending balance at Dec. 31, 2019	$ 406,634	$ 119	$ 642,628	$ (227,414)	$ (8,699)