Segment Information (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Operating income (loss)
Corporate SG & A	$ (76,350,000)	$ (70,042,000)
Profit sharing	(4,598,000)	(5,395,000)
Operating income	99,771,000	80,932,000
Assets
Cash and equivalents	160,982,000	342,919,000	361,363,000	395,156,000
Accounts receivable	741,309,000		859,835,000
Inventories	1,453,242,000		1,618,419,000
Deferred income taxes	33,414,000		35,503,000
Property, plant and equipment, net	3,085,587,000		3,123,906,000
Other	89,878,000		97,529,000
Total assets	6,735,838,000	5,913,857,000	7,311,027,000
Liabilities
Accounts payable	376,962,000		511,056,000
Income taxes payable	5,116,000		6,086,000
Accrued interest	51,800,000		50,405,000
Debt	2,700,000,000		3,000,000,000
Deferred income taxes	555,031,000		542,033,000
Liabilities	3,812,745,000	3,279,527,000
Operating Segment | Other.
Operating income (loss)
Corporate SG & A	(9,400,000)	(8,300,000)
Company-wide equity- based compensation	(5,900,000)	(4,600,000)
Profit sharing	(3,500,000)	(4,700,000)
Other, net	(1,100,000)	1,100,000
Operating income	(19,920,000)	(16,545,000)
Assets
Cash and equivalents	136,500,000	285,600,000
Accounts receivable	11,000,000	12,300,000
Inventories	12,800,000	13,500,000
Deferred income taxes	33,400,000	17,800,000
Property, plant and equipment, net	67,900,000	71,600,000
Debt issuance costs, net	37,000,000	24,400,000
Intra-company debt	146,600,000	153,800,000
Other	36,500,000	30,200,000
Total assets	481,726,000	609,206,000
Liabilities
Accounts payable	52,500,000	44,100,000
Income taxes payable	5,200,000	23,500,000
Accrued interest	51,600,000	21,700,000
Accrued profit sharing	3,500,000	4,800,000
Debt	2,600,100,000	2,031,400,000
Deferred income taxes	77,500,000	138,000,000
Other	20,200,000	26,800,000
Liabilities	$ 2,810,613,000	$ 2,290,332,000