Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales:	$ 280,086	$ 274,574	$ 761,459	$ 728,806
Cost of sales	209,807	205,839	572,359	548,991
Gross profit	70,279	68,735	189,100	179,815
Selling, general, and administrative expense	40,875	33,042	113,579	109,513
Income from operations	29,404	35,693	75,521	70,302
Interest expense	2,906	3,486	9,305	10,612
Other expense (income)	522	404	(50)	811
Income before taxes	25,976	31,803	66,266	58,879
Provision for income taxes	6,473	11,184	15,574	21,090
Income from continuing operations	19,503	20,619	50,692	37,789
Discontinued operations:
Loss before taxes	0	0	0	(644)
Benefit of income taxes	0	0	0	(239)
Loss from discontinued operations	0	0	0	(405)
Net income	$ 19,503	$ 20,619	$ 50,692	$ 37,384
Net earnings per share – Basic:
Income from continuing operations - Net earnings per share - Basic (in USD per share)	$ 0.61	$ 0.65	$ 1.59	$ 1.19
Income from discontinued operations - Net earnings per share - Basic (in USD per share)	0.00	0.00	0.00	(0.01)
Net earnings per share - Basic (in USD per share)	0.61	0.65	1.59	1.18
Net earnings per share - Diluted
Income from continuing operations - Net earnings per share - Diluted (in USD per share)	0.60	0.64	1.56	1.17
Income from discontinued operations - Net earnings per share - Diluted (in USD per share)	0.00	0.00	0.00	(0.01)
Net earnings per share - Diluted (in USD per share)	$ 0.60	$ 0.64	$ 1.56	$ 1.16
Weighted Average Number of Shares Outstanding
Weighted average basic shares outstanding (in shares)	32,115	31,703	31,922	31,700
Weighted average shares outstanding, diluted (in shares)	32,571	32,210	32,524	32,216