CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net sales	$ 1,995,686	$ 1,878,828
Cost of sales	1,533,561	1,374,760
Gross profit	462,125	504,068
Operating costs and expenses:
Selling and distribution	345,196	332,887
General and administrative	99,536	85,151
Amortization of intangibles	5,155	6,325
Facility closing and reorganization costs, net	9,286	1,166
Total operating costs and expenses	459,173	425,529
Operating income	2,952	78,539
Other (income) expense:
Interest expense	17,464	16,876
Other income, net	(956)	(997)
Total other expense	16,508	15,879
Income (loss) before income taxes	(13,556)	62,660
Income tax expense (benefit)	(3,797)	23,459
Net income (loss)	$ (9,759)	$ 39,201
Average common shares:
Basic (in shares)	90,709,802	91,567,119
Diluted (in shares)	90,709,802	92,168,303
Basic income (loss) per common share:
Net income (loss) (in dollars per share)	$ (0.11)	$ 0.43
Diluted income (loss) per common share:
Net income (loss) (in dollars per share)	(0.11)	0.43
Cash dividends declared per common share (in dollars per share)	$ 0.09	$ 0.09