Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, Adjusted Balance Retained Earnings	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Total
Beginning balance (in shares) at Dec. 31, 2017			52,969,869		20,220,227
Beginning balance at Dec. 31, 2017	$ 18,993	$ 18,993	$ 1	$ 201,672	$ (155,947)	$ 123,185	$ (1,467)	$ 167,444
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			4,645,000
Issuance of common stock				233,993				233,993
Issuance of common stock under employee plans, net (in shares)			1,136,925
Issuance of common stock under employee plans, net				(12,370)				(12,370)
Stock-based compensation				21,879				21,879
Issuance of common stock for business combination (in shares)			58,843
Issuance of common stock for business combination				8,226				8,226
Net income (loss)						29,205		29,205
Foreign currency translation adjustments							(46)	(46)
Ending balance (in shares) at Dec. 31, 2018			58,810,637		20,220,227
Ending balance at Dec. 31, 2018			$ 1	453,400	$ (155,947)	171,383	(1,513)	467,324
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee plans, net (in shares)			616,509
Issuance of common stock under employee plans, net				(3,937)				(3,937)
Stock-based compensation				78,809				78,809
Issuance of common stock for business combination (in shares)			70,613
Net income (loss)						882		882
Foreign currency translation adjustments							417	417
Ending balance (in shares) at Dec. 31, 2019			59,497,759		20,220,227
Ending balance at Dec. 31, 2019	$ (640)	$ (640)	$ 1	528,272	$ (155,947)	172,265	(1,096)	543,495
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			3,450,000
Issuance of common stock				306,779				306,779
Issuance of common stock under employee plans, net (in shares)			748,183
Issuance of common stock under employee plans, net				(7,514)				(7,514)
Stock-based compensation				133,572				133,572
Issuance of common stock for business combination (in shares)			70,613
Issuance of common stock for business combination				1,050				1,050
Net income (loss)						(1,724)		(1,724)
Foreign currency translation adjustments							1,237	1,237
Ending balance (in shares) at Dec. 31, 2020			63,766,555		20,220,227
Ending balance at Dec. 31, 2020			$ 1	$ 962,159	$ (155,947)	$ 169,901	$ 141	$ 976,255