Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance (in shares) at Dec. 31, 2020	33,633
Balance at Dec. 31, 2020	$ 34	$ 570,102	$ (91,969)	$ 3,435	$ 481,602
Increase (Decrease) in Stockholders' Equity
Net income			16,480		16,480
Foreign currency translation adjustments				(1,372)	(1,372)
Change in pension obligation				20	20
Exercise of stock options (in shares)	268
Exercise of stock options		2,512			2,512
Issuance of common shares on restricted stock units, net of shares withheld (in shares)	81
Issuance of common shares on restricted stock units, net of shares withheld		(2,354)			(2,354)
Stock-based compensation expense		2,407			2,407
Repurchase of common stock (in shares)	(303)
Repurchase of common stock		(5,468)	(6,167)		(11,635)
Balance (in shares) at Mar. 31, 2021	33,679
Balance at Mar. 31, 2021	$ 34	567,199	(81,656)	2,083	487,660
Balance (in shares) at Dec. 31, 2020	33,633
Balance at Dec. 31, 2020	$ 34	570,102	(91,969)	3,435	481,602
Increase (Decrease) in Stockholders' Equity
Net income					35,386
Foreign currency translation adjustments					(820)
Change in pension obligation					54
Balance (in shares) at Jun. 30, 2021	33,657
Balance at Jun. 30, 2021	$ 34	561,680	(70,281)	2,669	494,102
Balance (in shares) at Mar. 31, 2021	33,679
Balance at Mar. 31, 2021	$ 34	567,199	(81,656)	2,083	487,660
Increase (Decrease) in Stockholders' Equity
Net income			18,906		18,906
Foreign currency translation adjustments				552	552
Change in pension obligation				34	34
Exercise of stock options (in shares)	72
Exercise of stock options		563			563
Issuance of shares under Employee Stock Purchase Plan (in shares)	15
Issuance of shares under Employee Stock Purchase Plan		509			509
Issuance of common shares on restricted stock units, net of shares withheld (in shares)	214
Issuance of common shares on restricted stock units, net of shares withheld		(4,141)			(4,141)
Stock-based compensation expense		3,377			3,377
Repurchase of common stock (in shares)	(323)
Repurchase of common stock		(5,827)	(7,531)		(13,358)
Balance (in shares) at Jun. 30, 2021	33,657
Balance at Jun. 30, 2021	$ 34	561,680	(70,281)	2,669	494,102
Balance (in shares) at Dec. 31, 2021	33,240
Balance at Dec. 31, 2021	$ 33	559,883	(22,722)	1,765	538,959
Increase (Decrease) in Stockholders' Equity
Net income			41,614		41,614
Foreign currency translation adjustments				(1,186)	(1,186)
Change in pension obligation				9	9
Exercise of stock options (in shares)	41
Exercise of stock options		491			491
Issuance of common shares on restricted stock units, net of shares withheld (in shares)	67
Issuance of common shares on restricted stock units, net of shares withheld		(3,315)			(3,315)
Stock-based compensation expense		2,701			2,701
Repurchase of common stock (in shares)	(284)
Repurchase of common stock		(5,127)	(14,873)		(20,000)
Balance (in shares) at Mar. 31, 2022	33,064
Balance at Mar. 31, 2022	$ 33	554,633	4,019	588	559,273
Balance (in shares) at Dec. 31, 2021	33,240
Balance at Dec. 31, 2021	$ 33	559,883	(22,722)	1,765	538,959
Increase (Decrease) in Stockholders' Equity
Net income					85,804
Foreign currency translation adjustments					(3,871)
Change in pension obligation					17
Balance (in shares) at Jun. 30, 2022	33,094
Balance at Jun. 30, 2022	$ 33	549,401	39,582	(2,089)	586,927
Balance (in shares) at Mar. 31, 2022	33,064
Balance at Mar. 31, 2022	$ 33	554,633	4,019	588	559,273
Increase (Decrease) in Stockholders' Equity
Net income			44,189		44,189
Foreign currency translation adjustments				(2,685)	(2,685)
Change in pension obligation				8	8
Exercise of stock options (in shares)	25
Exercise of stock options		298			298
Issuance of shares under Employee Stock Purchase Plan (in shares)	15
Issuance of shares under Employee Stock Purchase Plan		711			711
Issuance of common shares on restricted stock units, net of shares withheld (in shares)	205
Issuance of common shares on restricted stock units, net of shares withheld		(5,896)			(5,896)
Stock-based compensation expense		3,527			3,527
Repurchase of common stock (in shares)	(215)
Repurchase of common stock		(3,872)	(8,626)		(12,498)
Balance (in shares) at Jun. 30, 2022	33,094
Balance at Jun. 30, 2022	$ 33	$ 549,401	$ 39,582	$ (2,089)	$ 586,927