Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2018	$ 385	$ 260,361	$ 34,984	$ (6,072)	$ (14,591)	$ 275,067
Balance, shares at Dec. 31, 2018	38,463				(1,484)
Net (loss) income			2,535			2,535
Other comprehensive (loss) income:
Foreign currency translation adjustment				(786)		(786)
Comprehensive (loss) income						1,749
Equity compensation	$ 2	4,417				4,419
Equity compensation, shares	245
Exercise of options	$ 3	3,001				3,004
Exercise of options, shares	301
Employee stock purchase plan		578				578
Employee stock purchase plan, shares	25
Redemption and repurchase of stock to cover tax withholdings	$ (1)	(2,663)				(2,664)
Redemption and repurchase of stock to cover tax withholdings, shares	(91)
Balance at Jun. 30, 2019	$ 389	265,694	37,519	(6,858)	$ (14,591)	282,153
Balance, shares at Jun. 30, 2019	38,943				(1,484)
Balance at Mar. 31, 2019	$ 388	261,991	34,687	(9,853)	$ (14,591)	272,622
Balance, shares at Mar. 31, 2019	38,756				(1,484)
Net (loss) income			2,832			2,832
Other comprehensive (loss) income:
Foreign currency translation adjustment				2,995		2,995
Comprehensive (loss) income						5,827
Equity compensation		2,439				2,439
Equity compensation, shares	40
Exercise of options	$ 2	1,551				1,553
Exercise of options, shares	156
Redemption and repurchase of stock to cover tax withholdings	$ (1)	(287)				(288)
Redemption and repurchase of stock to cover tax withholdings, shares	(9)
Balance at Jun. 30, 2019	$ 389	265,694	37,519	(6,858)	$ (14,591)	282,153
Balance, shares at Jun. 30, 2019	38,943				(1,484)
Balance at Dec. 31, 2019	$ 390	271,782	36,704	(8,589)	$ (14,591)	285,696
Balance, shares at Dec. 31, 2019	39,018				(1,484)
Net (loss) income			(10,354)			(10,354)
Other comprehensive (loss) income:
Foreign currency translation adjustment				(29)		(29)
Comprehensive (loss) income						(10,383)
Equity component of the convertible note issuance		16,426				16,426
Equity compensation	$ 3	5,367				5,370
Equity compensation, shares	267
Exercise of options	$ 1	486				487
Exercise of options, shares	44
Employee stock purchase plan		688				688
Employee stock purchase plan, shares	30
Redemption and repurchase of stock to cover tax withholdings	$ (1)	(1,727)				(1,728)
Redemption and repurchase of stock to cover tax withholdings, shares	(71)
Balance at Jun. 30, 2020	$ 393	293,022	26,350	(8,618)	$ (14,591)	296,556
Balance, shares at Jun. 30, 2020	39,288				(1,484)
Balance at Mar. 31, 2020	$ 392	273,821	30,039	(13,052)	$ (14,591)	276,609
Balance, shares at Mar. 31, 2020	39,219				(1,484)
Net (loss) income			(3,689)			(3,689)
Other comprehensive (loss) income:
Foreign currency translation adjustment				4,434		4,434
Comprehensive (loss) income						745
Equity component of the convertible note issuance		16,426				16,426
Equity compensation	$ 1	2,680				2,681
Equity compensation, shares	59
Exercise of options	$ 1	110				111
Exercise of options, shares	11
Redemption and repurchase of stock to cover tax withholdings	$ (1)	(15)				(16)
Redemption and repurchase of stock to cover tax withholdings, shares	(1)
Balance at Jun. 30, 2020	$ 393	$ 293,022	$ 26,350	$ (8,618)	$ (14,591)	$ 296,556
Balance, shares at Jun. 30, 2020	39,288				(1,484)