Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Income Statement [Abstract]
Net sales	$ 179,836	$ 213,959	$ 533,846	$ 599,171
Cost of sales	116,771	147,084	355,930	407,926
Gross profit	63,065	66,875	177,916	191,245
Selling, general and administrative expenses	39,335	36,764	116,182	128,488
Goodwill, Impairment Loss	0	50,307	0	50,307
Research and Development Expense	2,540	3,634	10,004	11,336
Amortization of Intangible Assets	2,624	4,826	7,898	11,269
Costs of Transaction Services Agreement	24	3,019	1,728	11,532
Cost of Acquired Retention Plans	0	5,703	0	17,110
Restructuring and severance costs	2,611	1,541	5,479	7,820
Gain (Loss) on Disposition of Business	0	0	234	(493)
Net (gain) loss on sale of assets	(31)	8	(16)	(5)
Operating income (loss)	15,962	(38,927)	36,407	(46,119)
Interest expense, net	3,646	5,327	12,232	14,382
Non-service pension and post retirement benefit income	(6,612)	(4,063)	(19,832)	(12,188)
Income from Transaction Services Agreement	(14)	(1,829)	(931)	(7,853)
Other (income) expense, net	(172)	(534)	275	(424)
Earnings (loss) from continuing operations before income taxes	19,114	(37,828)	44,663	(40,036)
Income tax expense (benefit)	4,447	679	10,156	(1,022)
Earnings from continuing operations	14,667	(38,507)	34,507	(39,014)
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	0	0	0	0
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	0	0	692
Earnings from discontinued operations, net of tax	0	0	0	692
Net earnings (loss)	$ 14,667	$ (38,507)	$ 34,507	$ (38,322)
Earnings per share:
Basic earnings per share from continuing operations	$ 0.53	$ (1.39)	$ 1.24	$ (1.41)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0.00	0.00	0.00	0.03
Basic earnings per share (in usd per share)	0.53	(1.39)	1.24	(1.38)
Diluted earnings per share from continuing operations	0.53	(1.39)	1.24	(1.41)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0.00	0.00	0.00	0.03
Diluted earnings per share (in usd per share)	$ 0.53	$ (1.39)	$ 1.24	$ (1.38)
Average shares outstanding:
Basic (in shares)	27,882	27,687	27,855	27,718
Diluted (in shares)	27,888	27,687	27,889	27,718