Segment Information (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Operating income (loss)
Gross profit increase from intra-company sales	$ 176,264,000	$ 201,264,000
Assets elimination
Elimination of intra-company receivables	753,301,000		642,363,000
Other	129,476,000		132,816,000
Total assets	5,956,574,000	6,043,627,000	5,815,416,000
Liabilities elimination
Elimination of intra-company payables	410,632,000		360,097,000
Liabilities	3,450,570,000	3,637,142,000
Eliminations
Operating income (loss)
Gross profit increase from intra-company sales	1,700,000	(2,100,000)
Assets elimination
Elimination of intra-company receivables	(49,400,000)	(27,900,000)
Elimination of intra-company debt	(156,000,000)	(149,600,000)
Other	(10,900,000)	(10,900,000)
Total assets	(216,259,000)	(188,429,000)
Liabilities elimination
Elimination of intra-company payables	(49,700,000)	(27,900,000)
Elimination of intra-company debt	(156,000,000)	(149,600,000)
Other liabilities	200,000	(1,100,000)
Liabilities	$ (205,527,000)	$ (178,607,000)