Condensed Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net sales	$ 874,642	$ 914,229	$ 1,667,379	$ 1,730,829
Cost of goods sold	746,935	780,572	1,425,795	1,474,935
Gross profit	127,707	133,657	241,584	255,894
Selling, general and administrative expenses	55,018	54,407	110,380	108,858
Rationalization charges	5,038	959	6,108	1,684
Income from operations	67,651	78,291	125,096	145,352
Interest and other debt expense	16,883	16,762	33,339	33,205
Income before income taxes	50,768	61,529	91,757	112,147
Provision for income taxes	17,453	19,285	31,871	36,599
Net income	$ 33,315	$ 42,244	$ 59,886	$ 75,548
Earnings per share:
Basic net income per share	$ 0.55	$ 0.70	$ 0.99	$ 1.23
Diluted net income per share	0.55	0.70	0.98	1.22
Dividends per share	$ 0.17	$ 0.16	$ 0.34	$ 0.32
Weighted average number of shares:
Basic (in shares)	60,504	60,473	60,477	61,631
Effect of dilutive securities (in shares)	356	255	364	268
Diluted (in shares)	60,860	60,728	60,841	61,899