Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales:	$ 1,047,439	$ 1,002,372	$ 986,918
Cost of sales	802,548	760,012	750,374
Gross profit	244,891	242,360	236,544
Selling, general, and administrative expense	157,052	146,840	143,448
Intangible asset impairment	0	1,552	247
Income from operations	87,839	93,968	92,849
Interest expense, net	2,205	12,064	14,032
Other expense	871	1,959	909
Income before taxes	84,763	79,945	77,908
Provision for income taxes	19,672	16,136	14,943
Income from continuing operations	65,091	63,809	62,965
Discontinued operations:
Loss before taxes	0	0	(644)
Benefit of income taxes	0	0	(239)
Loss from discontinued operations	0	0	(405)
Net income	$ 65,091	$ 63,809	$ 62,560
Net earnings per share – Basic:
Income from continuing operations (in dollars per share)	$ 2.01	$ 2.00	$ 1.98
Loss from discontinued operations (in dollars per share)	0	0	(0.01)
Net (loss) income (in dollars per share)	$ 2.01	$ 2.00	$ 1.97
Weighted average shares outstanding – Basic (in shares)	32,389	31,979	31,701
Net earnings per share – Diluted:
Income from continuing operations (in dollars per share)	$ 1.99	$ 1.96	$ 1.95
Loss from discontinued operations (in dollars per share)	0	0	(0.01)
Net (loss) income (in dollars per share)	$ 1.99	$ 1.96	$ 1.94
Weighted average shares outstanding – Diluted (in shares)	32,722	32,534	32,250