Segment Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Operating income (loss)
Corporate SG & A	$ (82,660)	$ (73,463)	$ (159,010)	$ (143,505)
Profit sharing	(5,031)	(10,469)	(9,629)	(15,864)
Operating income	77,559	131,905	177,330	212,837
Assets
Cash and equivalents	419,401	357,490	419,401	357,490	$ 160,982	$ 361,363	$ 342,919	$ 395,156
Accounts receivable	772,309		772,309			859,835
Inventories	1,292,069		1,292,069			1,618,419
Deferred income taxes	31,396		31,396			35,503
Property, plant and equipment, net	3,047,401		3,047,401			3,123,906
Other	87,670		87,670			97,529
Total assets	6,826,763	5,985,202	6,826,763	5,985,202		7,311,027
Liabilities
Accounts payable	446,698		446,698			511,056
Income taxes payable	2,411		2,411			6,086
Accrued interest	38,988		38,988			50,405
Debt	2,700,000		2,700,000			$ 3,000,000
Liabilities	3,902,063	3,025,992	3,902,063	3,025,992
Operating Segment | Other.
Operating income (loss)
Corporate SG & A	(8,100)	(11,000)	(17,500)	(19,300)
Company-wide equity- based compensation	(6,300)	(4,700)	(12,200)	(9,300)
Profit sharing	(3,500)	(8,900)	(7,000)	(13,600)
Other, net	(300)	400	(1,400)	1,500
Operating income	(18,191)	(24,159)	(38,111)	(40,704)
Assets
Cash and equivalents	355,600	299,900	355,600	299,900
Accounts receivable	8,400	14,400	8,400	14,400
Inventories	12,300	12,400	12,300	12,400
Deferred income taxes	31,400	17,700	31,400	17,700
Property, plant and equipment, net	67,100	70,900	67,100	70,900
Debt issuance costs, net	35,600	22,900	35,600	22,900
Intra-company debt	146,600	158,100	146,600	158,100
Other	37,000	28,200	37,000	28,200
Total assets	693,993	624,518	693,993	624,518
Liabilities
Accounts payable	47,800	46,000	47,800	46,000
Income taxes payable	2,600	19,400	2,600	19,400
Accrued interest	38,800	30,500	38,800	30,500
Accrued profit sharing	7,000	13,600	7,000	13,600
Debt	2,597,000	1,737,000	2,597,000	1,737,000
Deferred income taxes	79,200	120,500	79,200	120,500
Other	20,500	29,300	20,500	29,300
Liabilities	$ 2,792,947	$ 1,996,306	$ 2,792,947	$ 1,996,306