Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales	$ 463,327	$ 435,941
Cost of sales	329,220	311,595
Gross profit	134,107	124,346
Selling, general and administrative expenses	111,753	110,877
Restructuring costs	1,693	0
Net gain on sale of assets	(63)	(20)
Operating income	20,724	13,489
Interest expense, net	5,352	4,160
Non-service pension and post retirement benefit cost (income)	(3,029)	(719)
Other expense (income), net	(342)	(159)
Earnings before income taxes	18,743	10,207
Income tax expense	4,677	3,916
Net earnings	$ 14,066	$ 6,291
Earnings per share:
Basic earnings per share (in usd per share)	$ 0.51	$ 0.23
Diluted earnings per share (in usd per share)	$ 0.50	$ 0.22
Average shares outstanding:
Basic (in shares)	27,851	27,144
Diluted (in shares)	28,168	28,897
Dividends declared per share (in usd per share)	$ 0.20	$ 0.20