Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (loss)
Balance at Dec. 31, 2021	$ 94,437	$ 270	$ 110,330	$ 108,042	$ (107,265)	$ (16,940)
Balance, shares at Dec. 31, 2021		27,018,000			11,668,000
Employee Stock Purchase Plan share issuance	84		(3)		$ 87
Employee Stock Purchase Plan share issuance, shares					(9,000)
Stock Option Plan share issuance, net	215		(233)		$ 448
Stock Option Plan share issuance, net, shares					(49,000)
Restricted Stock Plan share issuance/forfeiture	(1,229)		(2,380)		$ 1,151
Restricted Stock Plan share issuance/forfeiture, shares					(111,000)
Equity-based compensation	1,176		1,176
Net income (loss)	4,280			4,280
Foreign currency adjustment	(4,567)					(4,567)
Pension loss adjustment, net of tax	911					911
Balance at Jul. 01, 2022	95,307	$ 270	108,890	112,322	$ (105,579)	(20,596)
Balance, shares at Jul. 01, 2022		27,018,000			11,499,000
Balance at Apr. 01, 2022	95,408	$ 270	109,422	110,282	$ (106,628)	(17,938)
Balance, shares at Apr. 01, 2022		27,018,000			11,599,000
Employee Stock Purchase Plan share issuance	47		(1)		$ 48
Employee Stock Purchase Plan share issuance, shares					(5,000)
Stock Option Plan share issuance, net	125		(139)		$ 264
Stock Option Plan share issuance, net, shares					(29,000)
Restricted Stock Plan share issuance/forfeiture	(258)		(995)		$ 737
Restricted Stock Plan share issuance/forfeiture, shares					(66,000)
Equity-based compensation	603		603
Net income (loss)	2,040			2,040
Foreign currency adjustment	(3,238)					(3,238)
Pension loss adjustment, net of tax	580					580
Balance at Jul. 01, 2022	95,307	$ 270	108,890	112,322	$ (105,579)	(20,596)
Balance, shares at Jul. 01, 2022		27,018,000			11,499,000
Balance at Dec. 31, 2022	$ 105,979	$ 270	109,868	114,651	$ (103,504)	(15,306)
Balance, shares at Dec. 31, 2022	27,017,824	27,018,000			11,274,000
Employee Stock Purchase Plan share issuance	$ 108		(30)		$ 138
Employee Stock Purchase Plan share issuance, shares					(15,000)
Stock Option Plan share issuance, net	84		(204)		$ 288
Stock Option Plan share issuance, net, shares					(24,000)
Restricted Stock Plan share issuance/forfeiture	(628)		(3,251)		$ 2,623
Restricted Stock Plan share issuance/forfeiture, shares					(262,000)
Equity-based compensation	867		867
Net income (loss)	185			185
Foreign currency adjustment	1,054					1,054
Pension loss adjustment, net of tax	104					104
Balance at Jun. 30, 2023	$ 107,753	$ 270	107,250	114,836	$ (100,455)	(14,148)
Balance, shares at Jun. 30, 2023	27,017,824	27,018,000			10,973,000
Balance at Mar. 31, 2023	$ 107,304	$ 270	108,240	114,966	$ (101,854)	(14,318)
Balance, shares at Mar. 31, 2023		27,018,000			11,112,000
Employee Stock Purchase Plan share issuance	52		(17)		$ 69
Employee Stock Purchase Plan share issuance, shares					(8,000)
Stock Option Plan share issuance, net	16		(87)		$ 103
Stock Option Plan share issuance, net, shares					(6,000)
Restricted Stock Plan share issuance/forfeiture	(181)		(1,408)		$ 1,227
Restricted Stock Plan share issuance/forfeiture, shares					(125,000)
Equity-based compensation	522		522
Net income (loss)	(130)			(130)
Foreign currency adjustment	110					110
Pension loss adjustment, net of tax	60					60
Balance at Jun. 30, 2023	$ 107,753	$ 270	$ 107,250	$ 114,836	$ (100,455)	$ (14,148)
Balance, shares at Jun. 30, 2023	27,017,824	27,018,000			10,973,000