CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance (in shares) at Dec. 31, 2018		81,996,839
Balance at beginning at Dec. 31, 2018	$ 1,075,518	$ 0	$ 1,139,462	$ 0	$ (11,021)	$ (52,923)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercises of employee stock options (in shares)		50,782
Issuance of common stock upon exercises of employee stock options	1,145		1,145
Issuance of common stock upon vesting of RSUs (in shares)		489,434
Stock-based compensation (inclusive of capitalized stock-based compensation)	32,474		32,474
Shares withheld related to net share settlement of equity awards	(12,827)		(12,827)
Repurchases of common stock	(102,126)			(102,126)
Retirement of common stock (in shares)		(2,847,226)
Retirement of common stock				102,126		(102,126)
Foreign currency adjustments	(711)				(711)
Net (loss) income	1,365					1,365
Balance (in shares) at Mar. 31, 2019		79,689,829
Balance at end at Mar. 31, 2019	$ 994,838	$ 0	1,160,254	0	(11,732)	(153,684)
Balance (in shares) at Dec. 31, 2019	71,185,468	71,185,468
Balance at beginning at Dec. 31, 2019	$ 754,991	$ 0	1,259,803	0	(11,759)	(493,053)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercises of employee stock options (in shares)	200,847	200,847
Issuance of common stock upon exercises of employee stock options	$ 2,585		2,585
Issuance of common stock upon vesting of RSUs (in shares)		501,531
Stock-based compensation (inclusive of capitalized stock-based compensation)	33,249		33,249
Shares withheld related to net share settlement of equity awards	(11,752)		(11,752)
Foreign currency adjustments	(1,104)				(1,104)
Net (loss) income	$ (15,503)					(15,503)
Balance (in shares) at Mar. 31, 2020	71,887,846	71,887,846
Balance at end at Mar. 31, 2020	$ 762,432	$ 0	$ 1,283,885	$ 0	$ (12,863)	$ (508,590)