Related Party Transactions (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Related Party Transaction [Line Items]
Sales	$ 1,680,641	$ 1,138,402	$ 1,315,834	$ 1,137,133	$ 1,297,830	$ 938,660	$ 1,338,167	$ 1,001,674	$ 5,272,010	$ 4,576,331	$ 3,393,791
Gross profit	91,169	78,316	102,650	85,870	86,431	64,964	122,772	78,685	358,005	352,852	281,679
Net income									75,565	96,825	64,881
Current assets	1,297,153				1,107,222				1,297,153	1,107,222
Current liabilities	992,807				794,251				992,807	794,251
Noncontrolling interest	611,445				538,842				611,445	538,842	464,559	406,276
Subsidiaries
Related Party Transaction [Line Items]
Sales									8,080,741	6,935,755	4,707,422
Gross profit									130,241	165,793	133,653
Income from continuing operations									34,161	90,510	59,046
Net income									32,451	87,673	57,691
Current assets	1,266,311				707,400				1,266,311	707,400
Non-current assets	326,776				336,554				326,776	336,554
Current liabilities	1,062,181				514,671				1,062,181	514,671
Non-current liabilities	123,991				100,315				123,991	100,315
Noncontrolling interest	$ 22,745				$ 26,799				$ 22,745	$ 26,799