Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Stock Trusts [Member]	Accumulated Other Comprehensive Income (loss) [Member]	Other [Member]
Balance at Dec. 31, 2013	$ 113,842	$ 270	$ 122,531	$ 112,277	$ (57,163)	$ (55,083)	$ (8,705)	$ (285)
Balance, shares at Dec. 31, 2013		27,018,000			8,488,000	3,363,000
Employee Stock Purchase Plan share issuance	323		145		$ 178
Employee Stock Purchase Plan share issuance, shares					(24,000)
Stock Option Plan share issuance, net	974		(2,082)		$ 3,056
Stock Option Plan share issuance, shares					(513,000)
Excess (deficient) tax benefits from equity-based compensation	1,964		1,964
Restricted stock plan share issuance/forfeiture	(2,745)		(247)		$ (2,498)
Restricted stock plan share issuance/forfeiture, shares					84,000
Deferred compensation plan share issuance	1,118		485		$ 348			$ 285
Deferred compensation plan share issuance, shares					(48,000)
Purchase of stock	(7,432)				$ (7,432)
Purchase of stock, shares					499,000
Equity-based compensation	3,088		3,088
Net income (loss)	10,350			10,350
Dividends declared	(3,628)			(3,628)
Foreign currency adjustment	(2,274)						(2,274)
Pension loss adjustment, net of tax	(4,614)						(4,614)
Balance at Dec. 31, 2014	110,966	$ 270	125,884	118,999	$ (63,511)	$ (55,083)	(15,593)
Balance, shares at Dec. 31, 2014		27,018,000			8,486,000	3,363,000
Employee Stock Purchase Plan share issuance	276		(5)		$ 281
Employee Stock Purchase Plan share issuance, shares					(37,000)
Stock Option Plan share issuance, net	2,405		(1,736)		$ 4,141
Stock Option Plan share issuance, shares					(551,000)
Excess (deficient) tax benefits from equity-based compensation	380		380
Restricted stock plan share issuance/forfeiture	(563)		(632)		$ (352)	$ 421
Restricted stock plan share issuance/forfeiture, shares					10,000	(98,000)
Deferred compensation plan share issuance	590		18		$ 572
Deferred compensation plan share issuance, shares					(76,000)
Purchase of stock	(1,406)				$ (1,406)
Purchase of stock, shares					182,000
Equity-based compensation	1,317		1,317
Net income (loss)	6,510			6,510
Dividends declared	(3,711)			(3,711)
Foreign currency adjustment	(1,875)						(1,875)
Pension loss adjustment, net of tax	2,828						2,828
Balance at Dec. 31, 2015	$ 117,717	$ 270	125,226	121,798	$ (60,275)	$ (54,662)	(14,640)
Balance, shares at Dec. 31, 2015	27,017,824	27,018,000			8,014,000	3,265,000
Employee Stock Purchase Plan share issuance	$ 215		(211)		$ 426
Employee Stock Purchase Plan share issuance, shares					(44,000)
Stock Option Plan share issuance, net	262		(820)		$ 1,082
Stock Option Plan share issuance, shares					(95,000)
Excess (deficient) tax benefits from equity-based compensation	(233)		(233)
Restricted stock plan share issuance/forfeiture	(382)		(1,241)		$ (1,286)	$ 2,145
Restricted stock plan share issuance/forfeiture, shares					259,000	(503,000)
Deferred compensation plan share issuance	549		(400)		$ 949
Deferred compensation plan share issuance, shares					(105,000)
Purchase of stock	(1,244)				$ (1,244)
Purchase of stock, shares					287,000
Termination of stock trusts	7				$ (52,510)	$ 52,517
Termination of stock trusts, shares					2,762,000	(2,762,000)
Equity-based compensation	1,626		1,626
Net income (loss)	(34,638)			(34,638)
Dividends declared	(2,937)			(2,937)
Foreign currency adjustment	(758)						(758)
Pension loss adjustment, net of tax	(1,365)						(1,365)
Balance at Dec. 31, 2016	$ 78,819	$ 270	$ 123,947	$ 84,223	$ (112,858)		$ (16,763)
Balance, shares at Dec. 31, 2016	27,017,824	27,018,000			11,078,000