Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net sales	$ 1,193,975	$ 1,262,006	$ 1,091,566
Cost of sales	782,817	829,648	738,170
Selling and administrative expenses	242,762	252,384	230,195
Total operating costs and expenses	1,025,579	1,082,032	968,365
Operating income	168,396	179,974	123,201
Interest expense	10,698	11,392	13,090
Other (income) expense, net	(248)	2,082	2,537
Income from continuing operations before income taxes	157,946	166,500	107,574
Income taxes	36,566	45,959	35,253
Income from continuing operations	121,380	120,541	72,321
(Loss) income from discontinued operations, net of income taxes of $0, $315 and $120,750, respectively (Note 3)	0	(2,171)	198,206
Net income	$ 121,380	$ 118,370	$ 270,527
Basic:
Income from continuing operations (in dollars per share)	$ 2.21	$ 2.20	$ 1.34
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	0.00	(0.04)	3.68
Net income (in dollars per share)	2.21	2.16	5.02
Diluted:
Income from continuing operations (in dollars per share)	2.19	2.16	1.31
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	0.00	(0.04)	3.61
Net income (in dollars per share)	2.19	2.12	4.92
Dividends	$ 0.48	$ 0.45	$ 0.42
Weighted average common shares outstanding:
Basic (in shares)	55,028,063	54,791,030	53,860,308
Diluted (in shares)	55,513,219	55,723,267	54,973,344