Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Income Statement [Abstract]
Net sales	$ 182,394	$ 177,890	$ 354,010	$ 385,212
Cost of sales	120,448	121,222	239,159	260,842
Gross profit	61,946	56,668	114,851	124,370
Selling, general and administrative expenses	38,719	38,396	76,847	91,724
Research and Development Expense	3,238	2,847	7,464	7,702
Amortization of Intangible Assets	2,637	3,637	5,274	6,443
Costs of Transaction Services Agreement	999	4,373	1,704	8,513
Cost of Acquired Retention Plans	0	5,704	0	11,407
Restructuring and severance costs	1,516	4,484	2,868	6,279
Gain (Loss) on Disposition of Business	0	0	234	(493)
Net loss (gain) on sale of assets	5	(3)	15	(13)
Operating income (loss)	14,832	(2,770)	20,445	(7,192)
Interest expense, net	4,335	5,808	8,586	9,055
Non-service pension and post retirement benefit income	(6,577)	(4,062)	(13,220)	(8,125)
Income from Transaction Services Agreement	(442)	(3,050)	(917)	(6,024)
Other expense (income), net	158	(108)	447	110
Earnings (loss) from continuing operations before income taxes	17,358	(1,358)	25,549	(2,208)
Income tax expense (benefit)	5,502	(1,258)	5,709	(1,701)
Earnings from continuing operations	11,856	(100)	19,840	(507)
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)	$ 11,856	$ (100)	$ 19,840	$ 185
Earnings per share:
Basic earnings per share from continuing operations	$ 0.43	$ (0.00)	$ 0.71	$ (0.02)
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)	0.43	0.00	0.71	0.01
Diluted earnings per share from continuing operations	0.42	(0.00)	0.71	(0.02)
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)	$ 0.42	$ 0.00	$ 0.71	$ 0.01
Average shares outstanding:
Basic (in shares)	27,867	27,659	27,841	27,734
Diluted (in shares)	27,913	27,659	27,890	27,734