CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total		Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ 346,356		$ 1	$ 835,444	$ 5,208	$ (494,297)
Beginning balance, Shares at Dec. 31, 2020			143,820,000
Common stock issued upon vesting of restricted stock units	0		$ 0	0	0	0
Common stock issued upon vesting of restricted stock units, Shares			967,000
Common stock issued upon stock option exercise	9,572		$ 0	9,572	0	0
Common stock issued upon stock option exercise, Shares			641,000
Issuance of restricted stock awards	0		$ 0	0	0	0
Issuance of restricted stock awards, Shares			274,000
Cancellation of restricted stock awards	0		$ 0	0	0	0
Cancellation of restricted stock awards, Shares			(64,000)
Stock-based compensation expense	24,158		$ 0	24,158	0	0
Comprehensive loss	(2,953)	[1]	0	0	(2,953)	0
Net loss	(29,647)		0	0	0	(29,647)
Ending balance at Mar. 31, 2021	347,486		$ 1	869,174	2,255	(523,944)
Ending balance, Shares at Mar. 31, 2021			145,638,000
Beginning Balance at Dec. 31, 2021	354,474		$ 2	971,604	414	(617,546)
Beginning balance, Shares at Dec. 31, 2021			150,398,000
Common stock issued upon vesting of restricted stock units	0		$ 0	0	0	0
Common stock issued upon vesting of restricted stock units, Shares			877,000
Common stock issued upon stock option exercise	$ 2,273		$ 0	2,273	0	0
Common stock issued upon stock option exercise, Shares	163,951		164,000
Issuance of restricted stock awards	$ 0		$ 0	0	0	0
Issuance of restricted stock awards, Shares			1,031,000
Issuance of performance stock awards	0		$ 0	0	0	0
Issuance of performance stock awards, shares			361,000
Repurchases of common stock, Shares			2,411,000
Repurchases of common stock, Value	36,376		$ 0	(36,376)	0	0
Stock-based compensation expense	26,973		0	26,973	0	0
Comprehensive loss	(947)	[1]	0	0	(947)	0
Net loss	(37,377)		0	0	0	(37,377)
Ending balance at Mar. 31, 2022	$ 309,020		$ 2	$ 964,474	$ (533)	$ (654,923)
Ending balance, Shares at Mar. 31, 2022			150,420,000

[1] Net of tax effect which was not material.