CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Issued	Common Stock in Treasury	Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance (in shares) at Dec. 31, 2017		23,760	(9,703)
Balance at Dec. 31, 2017	$ 253,549	$ 238	$ (262,065)	$ 265,195	$ (16,599)	$ 266,780
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11,924					11,924
Currency translation adjustment	(3,682)				(3,682)
Shares issued for employee benefit plan and compensation (in shares)		108
Shares issued for employee benefit plan and compensation	$ 1,062	$ 1		1,061
Purchase of treasury shares (in shares)	(413)		(413)
Purchase of treasury shares	$ (13,824)		$ (13,824)
Stock options exercised (in shares)	35	35
Stock options exercised	$ 864	$ 0		864
Shares Issued to directors (in shares)		30
Shares issued to directors	0	$ 0		0
Employee and director stock-based compensation	8,820			8,820
Performance-based common stock warrants	163			163
Balance (in shares) at Dec. 31, 2018		23,933	(10,116)
Balance at Dec. 31, 2018	262,960	$ 239	$ (275,889)	276,103	(20,281)	282,788
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,630					3,630
Currency translation adjustment	(2,500)				(2,500)
Shares issued for employee benefit plan and compensation (in shares)		133
Shares issued for employee benefit plan and compensation	$ 947	$ 2		945
Purchase of treasury shares (in shares)	(58)		(58)
Purchase of treasury shares	$ (1,928)		$ (1,928)
Stock options exercised (in shares)	22	22
Stock options exercised	$ 448	$ 0		448
Shares Issued to directors (in shares)		30
Shares issued to directors	0	$ 0		0
Employee and director stock-based compensation	8,845			8,845
Performance-based common stock warrants	1,997			1,997
Balance (in shares) at Dec. 31, 2019		24,118	(10,174)
Balance at Dec. 31, 2019	$ 274,399	$ 241	$ (277,817)	$ 288,338	$ (22,781)	$ 286,418