Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Treasury Stock	Stock Trusts	Accumulated Other Comprehensive Income (loss)	Other
Balance at Dec. 31, 2009	$ 71,718	$ 270	$ 112,473	$ 63,169	$ (44,585)	$ (55,083)	$ (4,526)
Balance, shares at Dec. 31, 2009		27,018,000			8,877,000	3,363,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan share issuance, shares	(101,000)				(22,000)
Employee Stock Purchase Plan share issuance	178		64		114
Exercised (in shares)					(181,000)
Stock Option Plan share issuance	736		(155)		891
Excess tax benefits from equity-based compensation	242		242
Restricted stock plan share issuance/forfeiture, shares					(58,000)
Restricted stock plan share issuance/forfeiture	(165)		(389)		224
Deferred compensation plan share issuance, shares					(34,000)
Deferred compensation plan share issuance	118		94		171			(147)
Purchase of stock, shares					381,000
Purchase of stock	(2,993)				(2,993)
Equity-based compensation	1,349		1,349
Net Income	8,372			8,372
Foreign currency adjustment	(1,093)						(1,093)
Pension loss adjustment, net of tax	(542)						(542)
Balance at Dec. 31, 2010	77,920	270	113,678	71,541	(46,178)	(55,083)	(6,161)	(147)
Balance, shares at Dec. 31, 2010		27,018,000			8,963,000	3,363,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan share issuance, shares	(465,000)				(22,000)
Employee Stock Purchase Plan share issuance	274		155		119
Exercised (in shares)					(637,000)
Stock Option Plan share issuance	1,927		(879)		2,806
Excess tax benefits from equity-based compensation	1,801		1,801
Restricted stock plan share issuance/forfeiture, shares					(50,000)
Restricted stock plan share issuance/forfeiture	(1,247)		(666)		(581)
Deferred compensation plan share issuance, shares					(21,000)
Deferred compensation plan share issuance	208		152		115			(59)
Purchase of stock, shares					308,000
Purchase of stock	(3,601)				(3,601)
Equity-based compensation	1,654		1,654
Net Income	11,938			11,938
Foreign currency adjustment	(326)						(326)
Pension loss adjustment, net of tax	(1,743)						(1,743)
Balance at Dec. 31, 2011	88,805	270	115,895	83,479	(47,320)	(55,083)	(8,230)	(206)
Balance, shares at Dec. 31, 2011	27,017,824	27,018,000			8,541,000	3,363,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan share issuance, shares	(461,000)				(19,000)
Employee Stock Purchase Plan share issuance	294		181		113
Exercised (in shares)					(476,000)
Stock Option Plan share issuance	223		(1,310)		1,533
Excess tax benefits from equity-based compensation	2,615		2,615
Restricted stock plan share issuance/forfeiture, shares					(70,000)
Restricted stock plan share issuance/forfeiture	(824)		(660)		(164)
Deferred compensation plan share issuance, shares					(26,000)
Deferred compensation plan share issuance	308		226		127			(45)
Purchase of stock, shares					326,000
Purchase of stock	(4,591)				(4,591)
Equity-based compensation	2,236		2,236
Net Income	16,165			16,165
Foreign currency adjustment	370						370
Pension loss adjustment, net of tax	(2,820)						(2,820)
Balance at Dec. 31, 2012	$ 102,781	$ 270	$ 119,183	$ 99,644	$ (50,302)	$ (55,083)	$ (10,680)	$ (251)
Balance, shares at Dec. 31, 2012	27,017,824	27,018,000			8,276,000	3,363,000