Segment Information (Details 3) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Operating income (loss)
Gross profit increase (reduction) from intra-company sales	$ 147,692,000	$ 182,136,000	$ 323,956,000	$ 383,400,000
Assets elimination
Elimination of intra-company receivables	773,127,000		773,127,000		642,363,000
Other	124,584,000		124,584,000		132,816,000
Total assets	5,735,910,000	5,971,380,000	5,735,910,000	5,971,380,000	5,815,416,000
Liabilities elimination
Elimination of intra-company payables	364,330,000		364,330,000		360,097,000
Liabilities	3,220,439,000	3,539,820,000	3,220,439,000	3,539,820,000
Eliminations
Operating income (loss)
Gross profit increase (reduction) from intra-company sales	3,000,000	1,000,000	4,700,000	(1,200,000)
Assets elimination
Elimination of intra-company receivables	(40,200,000)	(38,800,000)	(40,200,000)	(38,800,000)
Elimination of intra-company debt	(154,200,000)	(170,600,000)	(154,200,000)	(170,600,000)
Other	(7,800,000)	(13,500,000)	(7,800,000)	(13,500,000)
Total assets	(202,224,000)	(222,948,000)	(202,224,000)	(222,948,000)
Liabilities elimination
Elimination of intra-company payables	(40,500,000)	(41,200,000)	(40,500,000)	(41,200,000)
Elimination of intra-company debt	(154,200,000)	(170,600,000)	(154,200,000)	(170,600,000)
Other liabilities	1,300,000	(1,900,000)	1,300,000	(1,900,000)
Liabilities	$ (193,358,000)	$ (213,713,000)	$ (193,358,000)	$ (213,713,000)