Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (loss) [Member]
Balance at Dec. 31, 2018	$ 64,228	$ 270	$ 116,427	$ 82,548	$ (120,406)	$ (14,611)
Balance, shares at Dec. 31, 2018		27,018,000			12,746,000
Employee Stock Purchase Plan share issuance	79		(91)		$ 170
Employee Stock Purchase Plan share issuance, shares					(18,000)
Restricted stock plan share issuance/forfeiture	(153)		(1,311)		$ 1,158
Restricted stock plan share issuance/forfeiture, shares					52,000
Deferred compensation plan share issuance			(2,034)		$ 2,034
Deferred compensation plan share issuance, shares					(215,000)
Equity-based compensation	693		693
Net Income	1,575			1,575
Foreign currency adjustment	(478)					(478)
Pension gain adjustment, net of tax	97					97
Balance at Jun. 28, 2019	66,041	$ 270	113,684	84,123	$ (117,044)	(14,992)
Balance, shares at Jun. 28, 2019		27,018,000			12,565,000
Balance at Mar. 29, 2019	64,273	$ 270	115,074	83,180	$ (118,860)	(15,391)
Balance, shares at Mar. 29, 2019		27,018,000			12,741,000
Employee Stock Purchase Plan share issuance	41		(48)		$ 89
Employee Stock Purchase Plan share issuance, shares					(9,000)
Restricted stock plan share issuance/forfeiture	(59)		(1,786)		$ 1,727
Restricted stock plan share issuance/forfeiture, shares					(167,000)
Equity-based compensation	444		444
Net Income	943			943
Foreign currency adjustment	445					445
Pension gain adjustment, net of tax	(46)					(46)
Balance at Jun. 28, 2019	66,041	$ 270	113,684	84,123	$ (117,044)	(14,992)
Balance, shares at Jun. 28, 2019		27,018,000			12,565,000
Balance at Dec. 31, 2019	$ 66,236	$ 270	112,096	86,673	$ (114,261)	(18,542)
Balance, shares at Dec. 31, 2019	27,017,824	27,018,000			12,311,000
Employee Stock Purchase Plan share issuance	$ 63		(65)		$ 128
Employee Stock Purchase Plan share issuance, shares					(14,000)
Restricted stock plan share issuance/forfeiture	(160)		(4,973)		$ 4,813
Restricted stock plan share issuance/forfeiture, shares					(462,000)
Equity-based compensation	1,149		1,149
Net Income	2,903			2,903
Foreign currency adjustment	(56)					(56)
Pension gain adjustment, net of tax	61					61
Balance at Jun. 26, 2020	$ 70,196	$ 270	108,207	89,576	$ (109,320)	(18,537)
Balance, shares at Jun. 26, 2020	27,017,824	27,018,000			11,835,000
Balance at Mar. 27, 2020	$ 67,200	$ 270	109,112	87,817	$ (110,818)	(19,181)
Balance, shares at Mar. 27, 2020		27,018,000			11,950,000
Employee Stock Purchase Plan share issuance	35		(42)		$ 77
Employee Stock Purchase Plan share issuance, shares					(9,000)
Restricted stock plan share issuance/forfeiture	(79)		(1,500)		$ 1,421
Restricted stock plan share issuance/forfeiture, shares					(106,000)
Equity-based compensation	637		637
Net Income	1,759			1,759
Foreign currency adjustment	732					732
Pension gain adjustment, net of tax	(88)					(88)
Balance at Jun. 26, 2020	$ 70,196	$ 270	$ 108,207	$ 89,576	$ (109,320)	$ (18,537)
Balance, shares at Jun. 26, 2020	27,017,824	27,018,000			11,835,000