CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance at Dec. 31, 2019	$ 9,504	$ (238)	$ 9,266	$ 376	$ 376	$ 354,326	$ 354,326	$ (12,551)	$ (12,551)	$ (331,951)	$ (238)	$ (332,189)	$ (696)	$ (696)
Beginning balance (in shares) at Dec. 31, 2019				37,460,000	37,460,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(15,748)									(15,748)
Share-based compensation expense	3,501					3,501
Issuance of common stock upon vesting of restricted stock units	0			$ 4		(4)
Issuance of common stock upon vesting of restricted stock units (in shares)				354,000
Effect of shares withheld to cover taxes	(4,146)					(4,146)
Total other comprehensive income (loss)	(8,873)							(8,873)
Ending balance at Mar. 31, 2020	(16,000)			$ 380		353,677		(21,424)		(347,937)			(696)
Ending balance (in shares) at Mar. 31, 2020				37,814,000
Beginning balance at Dec. 31, 2019	9,504	$ (238)	$ 9,266	$ 376	$ 376	354,326	$ 354,326	(12,551)	$ (12,551)	(331,951)	$ (238)	$ (332,189)	(696)	$ (696)
Beginning balance (in shares) at Dec. 31, 2019				37,460,000	37,460,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	22,121
Total other comprehensive income (loss)	(7,849)
Ending balance at Sep. 30, 2020	32,301			$ 383		363,082		(20,400)		(310,068)			(696)
Ending balance (in shares) at Sep. 30, 2020				38,135,000
Beginning balance at Mar. 31, 2020	(16,000)			$ 380		353,677		(21,424)		(347,937)			(696)
Beginning balance (in shares) at Mar. 31, 2020				37,814,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	31,054									31,054
Share-based compensation expense	8,984					8,984
Issuance in connection with the exercise of stock options	38					38
Issuance in connection with the exercise of stock options (in shares)				3,000
Issuance of common stock upon vesting of restricted stock units	0			$ 3		(3)
Issuance of common stock upon vesting of restricted stock units (in shares)				316,000
Effect of shares withheld to cover taxes	(2,682)					(2,682)
Total other comprehensive income (loss)	(546)							(546)
Ending balance at Jun. 30, 2020	20,848			$ 383		360,014		(21,970)		(316,883)			(696)
Ending balance (in shares) at Jun. 30, 2020				38,133,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	6,815									6,815
Share-based compensation expense	3,081					3,081
Issuance of common stock upon vesting of restricted stock units (in shares)				2,000
Effect of shares withheld to cover taxes	(13)					(13)
Total other comprehensive income (loss)	1,570							1,570
Ending balance at Sep. 30, 2020	32,301			$ 383		363,082		(20,400)		(310,068)			(696)
Ending balance (in shares) at Sep. 30, 2020				38,135,000
Beginning balance at Dec. 31, 2020	$ 50,977			$ 383		365,503		(20,215)		(293,998)			(696)
Beginning balance (in shares) at Dec. 31, 2020	38,178,975			38,179,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (3,330)									(3,330)
Share-based compensation expense	3,179					3,179
Issuance in connection with the exercise of stock options	366					366
Issuance in connection with the exercise of stock options (in shares)				29,000
Issuance of common stock upon vesting of restricted stock units	0			$ 4		(4)
Issuance of common stock upon vesting of restricted stock units (in shares)				365,000
Effect of shares withheld to cover taxes	(4,520)					(4,520)
Total other comprehensive income (loss)	2,572							2,572
Ending balance at Mar. 31, 2021	49,244			$ 387		364,524		(17,643)		(297,328)			(696)
Ending balance (in shares) at Mar. 31, 2021				38,573,000
Beginning balance at Dec. 31, 2020	$ 50,977			$ 383		365,503		(20,215)		(293,998)			(696)
Beginning balance (in shares) at Dec. 31, 2020	38,178,975			38,179,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 27,946
Total other comprehensive income (loss)	5,238
Ending balance at Sep. 30, 2021	$ 89,522			$ 389		370,858		(14,977)		(266,052)			(696)
Ending balance (in shares) at Sep. 30, 2021	38,735,472			38,740,000
Beginning balance at Mar. 31, 2021	$ 49,244			$ 387		364,524		(17,643)		(297,328)			(696)
Beginning balance (in shares) at Mar. 31, 2021				38,573,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	10,159									10,159
Share-based compensation expense	3,239					3,239
Issuance in connection with the exercise of stock options	5			$ 1		4
Issuance in connection with the exercise of stock options (in shares)				80,000
Issuance of common stock upon vesting of restricted stock units	0			$ 1		(1)
Issuance of common stock upon vesting of restricted stock units (in shares)				69,000
Effect of shares withheld to cover taxes	(40)					(40)
Total other comprehensive income (loss)	1,285							1,285
Ending balance at Jun. 30, 2021	63,892			$ 389		367,726		(16,358)		(287,169)			(696)
Ending balance (in shares) at Jun. 30, 2021				38,722,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	21,117									21,117
Share-based compensation expense	2,989					2,989
Issuance in connection with the exercise of stock options	153					153
Issuance in connection with the exercise of stock options (in shares)				12,000
Issuance of common stock upon vesting of restricted stock units (in shares)				6,000
Effect of shares withheld to cover taxes	(10)					(10)
Total other comprehensive income (loss)	1,381							1,381
Ending balance at Sep. 30, 2021	$ 89,522			$ 389		$ 370,858		$ (14,977)		$ (266,052)			$ (696)
Ending balance (in shares) at Sep. 30, 2021	38,735,472			38,740,000