Consolidated Statements of Changes in Stockholders’ Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2017		37,765
Beginning balance at Dec. 31, 2017	$ 23,291	$ 378	$ 232,960	$ (209,013)	$ (1,034)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	40,518			40,518
Forfeiture of dividend equivalent right	355			355
Other comprehensive income (loss)	(74)				(74)
Stock option exercises and employee stock plan purchases (in shares)		223
Stock option exercises and employee stock plan purchases	1,580	$ 2	1,578
Vesting of restricted stock awards and units (in shares)		672
Vesting of restricted stock awards	0	$ 7	(7)
Shares withheld to cover taxes (in shares)		(194)
Shares withheld to cover taxes	(3,386)	$ (2)	(3,384)
Stock-based compensation	8,718		8,718
Ending balance (in shares) at Dec. 31, 2018		38,466
Ending balance at Dec. 31, 2018	71,002	$ 385	239,865	(168,140)	(1,108)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	31,667			31,667
Other comprehensive income (loss)	148				148
Stock option exercises and employee stock plan purchases (in shares)		95
Stock option exercises and employee stock plan purchases	1,746	$ 1	1,745
Vesting of restricted stock awards and units (in shares)		796
Vesting of restricted stock awards	0	$ 8	(8)
Shares withheld to cover taxes (in shares)		(106)
Shares withheld to cover taxes	(2,454)	$ (1)	(2,453)
Stock-based compensation	12,492		12,492
Ending balance (in shares) at Dec. 31, 2019		39,251
Ending balance at Dec. 31, 2019	114,601	$ 393	251,641	(136,473)	(960)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(13,473)			(13,473)
Other comprehensive income (loss)	(1,088)				(1,088)
Stock option exercises and employee stock plan purchases (in shares)		73
Stock option exercises and employee stock plan purchases	760	$ 1	759
Vesting of restricted stock awards and units (in shares)		847
Vesting of restricted stock awards	0	$ 8	(8)
Shares withheld to cover taxes (in shares)		(141)
Shares withheld to cover taxes	(2,129)	$ (2)	(2,127)
Issuance of common stock (in shares)		26,845
Issuance of common stock, net of $3,776 issuance costs	394,334	$ 269	394,065
Fair value of replacement stock options related to precombination services	7,125		7,125
Stock-based compensation	14,075		14,075
Ending balance (in shares) at Dec. 31, 2020		66,875
Ending balance at Dec. 31, 2020	$ 514,205	$ 669	$ 665,530	$ (149,946)	$ (2,048)