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	Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2013		22,344	(6,639)
Beginning balance at Dec. 31, 2013	$ 291,270	$ 223	$ (104,980)	$ 199,513	$ 2,982	$ 193,532	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	32,534					32,534	0
Currency translation adjustment	(7,428)				(7,428)
Shares issued for employee benefit plan and compensation (in shares)		160
Shares issued for employee benefit plan and compensation	$ 847	$ 2		845
Purchase of treasury shares (in shares)	(384)		(384)
Purchase of treasury shares	$ (16,168)		$ (16,168)
Stock options exercised (in shares)	391	391
Stock options exercised	$ 8,122	$ 4		8,118
Shares Issued to Directors (in shares)		15	15
Shares issued to Directors	0		$ 210	(210)
Employee and director stock-based compensation	6,444			6,444
Ending balance (in shares) at Dec. 31, 2014		22,910	(7,008)
Ending balance at Dec. 31, 2014	315,621	$ 229	$ (120,938)	214,710	(4,446)	226,066	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	29,173					29,174	(1)
Currency translation adjustment	(11,353)				(11,353)
Shares issued for employee benefit plan and compensation (in shares)		165
Shares issued for employee benefit plan and compensation	$ 868	$ 2		866
Purchase of treasury shares (in shares)	(1,817)		(1,817)
Purchase of treasury shares	$ (89,395)		$ (89,395)
Stock options exercised (in shares)	71	71
Stock options exercised	$ 1,712	$ 1		1,711
Shares Issued to Directors (in shares)		30
Shares issued to Directors	0
Employee and director stock-based compensation	7,913			7,913
Tax benefit from exercise of non-qualified stock options and vested restricted stock	3,069			3,069
Performance-based common stock warrants	378						378
Distribution to noncontrolling interest	(78)						(78)
Ending balance (in shares) at Dec. 31, 2015		23,176	(8,825)
Ending balance at Dec. 31, 2015	257,908	$ 232	$ (210,333)	228,269	(15,799)	255,240	299
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	20,384					20,354	30
Currency translation adjustment	(7,022)				(7,022)
Shares issued for employee benefit plan and compensation (in shares)		130
Shares issued for employee benefit plan and compensation	$ 913	$ 1		912
Purchase of treasury shares (in shares)	(198)		(198)
Purchase of treasury shares	$ (12,647)		$ (12,647)
Stock options exercised (in shares)	239	239
Stock options exercised	$ 6,244	$ 3		6,241
Shares Issued to Directors (in shares)		30
Shares issued to Directors	0
Employee and director stock-based compensation	10,324			10,324
Tax benefit from exercise of non-qualified stock options and vested restricted stock	2,007			2,007
Performance-based common stock warrants	2,728			2,728
Deconsolidation of Encore Controls LLC	(329)						(329)
Ending balance (in shares) at Dec. 31, 2016		23,575	(9,023)
Ending balance at Dec. 31, 2016	$ 280,510	$ 236	$ (222,980)	$ 250,481	$ (22,821)	$ 275,594	$ 0