CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Beginning balance (in shares) at Dec. 31, 2019		48,526
Beginning balance at Dec. 31, 2019	$ 160,206	$ 121	$ 582,504	$ (7,871)	$ (414,548)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	4,337			(1,970)	6,307
Issuance of common stock upon exercise of stock options (in shares)		52
Issuance of common stock upon exercise of stock options	231		231
Issuance of common stock for vested restricted stock units (in shares)		114
Issuance of common stock for vested restricted stock units	1	$ 1
Tax withholding related to vesting of restricted stock units (in shares)		(30)
Tax withholding related to vesting of restricted stock units	(219)		(219)
Stock-based compensation costs	2,682		2,682
Ending Balance (in shares) at Mar. 31, 2020		48,662
Ending balance at Mar. 31, 2020	167,238	$ 122	585,198	(9,841)	(408,241)
Beginning balance (in shares) at Dec. 31, 2020		50,457
Beginning balance at Dec. 31, 2020	180,407	$ 126	597,460	1,735	(418,914)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(13,035)			(2,343)	(10,692)
Issuance of common stock upon exercise of stock options (in shares)		199
Issuance of common stock upon exercise of stock options	1,109		1,109
Issuance of common stock for vested restricted stock units (in shares)		503
Issuance of common stock for vested restricted stock units	0	$ 2	(2)
Tax withholding related to vesting of restricted stock units (in shares)		(150)
Tax withholding related to vesting of restricted stock units	(1,835)		(1,835)
Stock-based compensation costs	3,012		3,012
Ending Balance (in shares) at Mar. 31, 2021		51,009
Ending balance at Mar. 31, 2021	$ 169,658	$ 128	$ 599,744	$ (608)	$ (429,606)