CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Company Shares held by SERP [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2008	$ 4,502	$ 121,968	$ (2,799)	$ (1,966)	$ 317,521	$ 807	$ 440,033
Balance (in shares) at Dec. 31, 2008	22,508,332
Net income					3,068	38	3,106
Other comprehensive income (loss):
Change in unrecognized pension and post retirement cost, net of income taxes			414				414
Foreign currency translation adjustments			6,936			(506)	6,430
Comprehensive income (loss)						(468)	9,950
Increase (decrease) in ownership percentage of subsidiary						18	18
Stock-based compensation (in shares)	7,947
Stock-based compensation	1	1,406					1,407
Exercise of stock options, including tax benefit (in shares)	35,004
Exercise of stock options, including tax benefit	7	923					930
Purchase of Company stock held by SERP, net		84		(162)			(78)
Balance at Dec. 31, 2009	4,510	124,381	4,551	(2,128)	320,589	357	452,260
Balance (in shares) at Dec. 31, 2009	22,551,283
Net income					32,430	142	32,572
Other comprehensive income (loss):
Change in unrecognized pension and post retirement cost, net of income taxes			(224)				(224)
Foreign currency translation adjustments			3,719			100	3,819
Comprehensive income (loss)						242	36,167
Increase (decrease) in ownership percentage of subsidiary						(1)	(1)
Stock-based compensation (in shares)	5,315
Stock-based compensation	1	2,394					2,395
Exercise of stock options, including tax benefit (in shares)	90,224
Exercise of stock options, including tax benefit	18	1,992					2,010
Purchase of Company stock held by SERP, net		64		(89)			(25)
Balance at Dec. 31, 2010	4,529	128,831	8,046	(2,217)	353,019	598	492,806
Balance (in shares) at Dec. 31, 2010	22,646,822						22,646,822
Net income					39,918	102	40,020
Other comprehensive income (loss):
Change in unrecognized pension and post retirement cost, net of income taxes			(1,711)				(1,711)
Foreign currency translation adjustments			(5,494)			(93)	(5,587)
Comprehensive income (loss)						9	32,722
Increase (decrease) in ownership percentage of subsidiary						(1)	(1)
Stock-based compensation (in shares)	5,725
Stock-based compensation	1	2,799					2,800
Exercise of stock options, including tax benefit (in shares)	58,901
Exercise of stock options, including tax benefit	12	1,110					1,122
Purchase of Company stock held by SERP, net		4		(270)			(266)
Balance at Dec. 31, 2011	$ 4,542	$ 132,744	$ 841	$ (2,487)	$ 392,937	$ 606	$ 529,183
Balance (in shares) at Dec. 31, 2011	22,711,448						22,711,448