Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Treasury Stock
Beginning balance, shares at Dec. 31, 2019		56,448
Balance at beginning of period at Dec. 31, 2019	$ 154,028	$ 1,545	$ 895,899	$ (854)	$ (702,576)	$ (39,986)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	13,960		13,960
Issuance of common stock under equity incentive plans, net of forfeitures (in shares)		2,454
Issuance of common stock under equity incentive plans, net of forfeitures	18,127	$ 60	18,067
Issuance of common stock in connection with public offering, net of expenses (in shares)		3,220
Issuance of common stock in connection with public offering, net of expenses	60,063	$ 82	59,981
Treasury stock retirement	0	$ (134)	(39,852)			39,986
Net income	33,484				33,484
Other comprehensive income (loss)	663			663
Ending balance, shares at Dec. 31, 2020		62,122
Balance at end of period at Dec. 31, 2020	280,325	$ 1,553	948,055	(191)	(669,092)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	24,230		24,230
Issuance of common stock under equity incentive plans, net of forfeitures (in shares)		2,152
Issuance of common stock under equity incentive plans, net of forfeitures	25,624	$ 54	25,570
Net income	238,378				238,378
Other comprehensive income (loss)	$ (129)			(129)
Ending balance, shares at Dec. 31, 2021	64,274	64,274
Balance at end of period at Dec. 31, 2021	$ 568,428	$ 1,607	997,855	(320)	(430,714)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	44,826		44,826
Issuance of common stock under equity incentive plans, net of forfeitures (in shares)		1,461
Issuance of common stock under equity incentive plans, net of forfeitures	27,456	$ 37	27,419
Net income	41,010				41,010
Other comprehensive income (loss)	$ (2,153)			(2,153)
Ending balance, shares at Dec. 31, 2022	65,735	65,735
Balance at end of period at Dec. 31, 2022	$ 679,567	$ 1,644	$ 1,070,100	$ (2,473)	$ (389,704)	$ 0