Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Additional Paid-In Capital [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Treasury Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Total
Balance at Dec. 31, 2017		$ 376		$ 249,935	$ 215	$ 37,609		$ 1,857		$ (12,719)	$ 215	$ 277,058
Balance, shares at Dec. 31, 2017		37,618,000								(1,386,000)
Net (loss) income						(2,840)						(2,840)
Other comprehensive (loss) income:
Foreign currency translation gain (loss), net of tax								(7,929)				(7,929)
Comprehensive loss												(10,769)
Equity compensation		$ 3		6,806								6,809
Equity compensation, shares		287,000
Exercise of options		$ 5		4,382						$ (1,872)		2,515
Exercise of options, shares		578,000								(98,000)
Employee stock purchase plan		$ 1		1,338								$ 1,339
Employee stock purchase plan, shares		83,000										83,000
Redemption and repurchase of stock to cover tax withholdings				(2,100)								$ (2,100)
Redemption and repurchase of stock to cover tax withholdings, shares		(103,000)
Balance at Dec. 31, 2018		$ 385		260,361		34,984		(6,072)		$ (14,591)		275,067
Balance, shares at Dec. 31, 2018		38,463,000								(1,484,000)
Net (loss) income						1,720						1,720
Other comprehensive (loss) income:
Foreign currency translation gain (loss), net of tax								(2,517)				(2,517)
Comprehensive loss												(797)
Equity compensation		$ 2		9,409								9,411
Equity compensation, shares		254,000
Exercise of options		$ 3		3,292								3,295
Exercise of options, shares		334,000
Employee stock purchase plan		$ 1		1,462								$ 1,463
Employee stock purchase plan, shares		61,000										61,000
Redemption and repurchase of stock to cover tax withholdings		$ (1)		(2,742)								$ (2,743)
Redemption and repurchase of stock to cover tax withholdings, shares		(94,000)
Balance at Dec. 31, 2019		$ 390		271,782		36,704		(8,589)		$ (14,591)		285,696
Balance, shares at Dec. 31, 2019		39,018,000								(1,484,000)
Net (loss) income						(16,682)						(16,682)
Other comprehensive (loss) income:
Foreign currency translation gain (loss), net of tax								15,332				15,332
Comprehensive loss												(1,350)
Stock issued for the Ascyrus Acquisition		$ 10		19,990								20,000
Stock issued for the Ascyrus Acquisition, shares		992,000
Equity component of the convertible note issuance				16,426								16,426
Equity compensation		$ 3		7,501								7,504
Equity compensation, shares		296,000
Exercise of options		$ 1		927						$ (57)		871
Exercise of options, shares		89,000								(3,000)
Employee stock purchase plan		$ 1		1,560								$ 1,561
Employee stock purchase plan, shares		83,000										83,000
Redemption and repurchase of stock to cover tax withholdings		$ (1)		(1,994)								$ (1,995)
Redemption and repurchase of stock to cover tax withholdings, shares		(84,000)
Balance at Dec. 31, 2020		$ 404		$ 316,192		$ 20,022		$ 6,743		$ (14,648)		$ 328,713
Balance, shares at Dec. 31, 2020		40,394,000								(1,487,000)