Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 288,332	$ 300,573
Cost of sales	186,255	198,355
Selling and administrative expenses	60,550	58,323
Total operating costs and expenses	246,805	256,678
Operating income	41,527	43,895
Interest expense	2,991	2,720
Other expense (income), net	227	81
Income before income taxes	38,309	41,094
Income taxes	9,461	12,018
Net income	$ 28,848	$ 29,076
Per common share:
Basic (in dollars per share)	$ 0.53	$ 0.53
Diluted (in dollars per share)	0.53	0.52
Dividends (in dollars per share)	$ 0.12	$ 0.12
Weighted average common shares outstanding:
Basic (in shares)	54,245,728	55,086,882
Diluted (in shares)	54,672,773	55,658,797