Condensed Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 1,059,103	$ 1,021,814	$ 2,071,385	$ 1,827,220
Cost of goods sold	885,853	863,120	1,738,101	1,550,547
Gross profit	173,250	158,694	333,284	276,673
Selling, general and administrative expenses	78,253	88,654	154,998	157,313
Rationalization charges	492	3,038	1,195	3,923
Other pension and postretirement income	(9,612)	(8,231)	(19,210)	(16,557)
Income before interest and income taxes	104,117	75,233	196,301	131,994
Interest and other debt expense before loss on early extinguishment of debt	29,922	29,207	60,401	49,625
Loss on early extinguishment of debt	2,493	4,375	2,493	7,052
Interest and other debt expense	32,415	33,582	62,894	56,677
Income before income taxes	71,702	41,651	133,407	75,317
Provision for income taxes	16,359	13,725	32,340	24,160
Net income	$ 55,343	$ 27,926	$ 101,067	$ 51,157
Earnings per share
Basic net income per share (usd per share)	$ 0.50	$ 0.25	$ 0.91	$ 0.46
Diluted net income per share (usd per share)	0.50	0.25	0.91	0.46
Dividends per share (usd per share)	$ 0.10	$ 0.09	$ 0.20	$ 0.18
Weighted average number of shares
Basic (in shares)	110,645	110,358	110,566	110,291
Effect of dilutive securities (in shares)	929	968	998	976
Diluted (in shares)	111,574	111,326	111,564	111,267