Segment Information (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Operating income (loss)
Gross profit increase from intra-company sales	$ 187,042,000	$ 163,304,000
Assets elimination
Elimination of intra-company receivables	769,741,000		902,825,000
Other	89,878,000		97,529,000
Total assets	6,735,838,000	5,913,857,000	7,311,027,000
Liabilities elimination
Elimination of intra-company payables	376,962,000		511,056,000
Liabilities	3,812,745,000	3,279,527,000
Eliminations
Operating income (loss)
Gross profit increase from intra-company sales	3,900,000	4,200,000
Assets elimination
Elimination of intra-company receivables	(37,600,000)	(65,100,000)
Elimination of intra-company debt	(146,600,000)	(153,800,000)
Other	(5,200,000)	(9,300,000)
Total assets	(189,364,000)	(228,175,000)
Liabilities elimination
Elimination of intra-company payables	(38,000,000)	(65,500,000)
Elimination of intra-company debt	(146,600,000)	(153,800,000)
Other	1,100,000	1,200,000
Liabilities	$ (183,468,000)	$ (218,081,000)