Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Net sales	$ 1,262,006	$ 1,091,566	$ 928,780
Cost of sales	829,648	738,170	655,653
Selling and administrative expenses	252,384	230,195	165,996
Total operating costs and expenses	1,082,032	968,365	821,649
Operating income	179,974	123,201	107,131
Interest expense	11,392	13,090	12,238
Other expense (income), net	2,082	2,537	2,631
Income from continuing operations before income taxes	166,500	107,574	92,262
Income taxes	45,959	35,253	12,432
Income from continuing operations	120,541	72,321	79,830
(Loss) income from discontinued operations, net of income taxes of $315, $120,750 and $10,831, respectively (Note 2)	(2,171)	198,206	15,419
Net income	$ 118,370	$ 270,527	$ 95,249
Basic:
Income from continuing operations (in dollars per share)	$ 2.20	$ 1.34	$ 1.46
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	$ (0.04)	$ 3.68	$ 0.28
Net income (in dollars per share)	$ 2.16	$ 5.02	$ 1.74
Diluted:
Income from continuing operations (in dollars per share)	$ 2.16	$ 1.31	$ 1.44
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	$ (0.04)	$ 3.61	$ 0.28
Net income (in dollars per share)	$ 2.12	$ 4.92	$ 1.72
Dividends	$ 0.45	$ 0.42	$ 0.40
Weighted average common shares outstanding:
Basic (in shares)	54,791,030	53,860,308	54,626,453
Diluted (in shares)	55,723,267	54,973,344	55,224,457