Related Party Transactions (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]
Sales	$ 1,271,768	$ 952,927	$ 1,312,082	$ 1,003,294	$ 1,584,266	$ 1,181,374	$ 1,566,964	$ 1,271,970	$ 4,540,071	$ 5,604,574	$ 5,272,010
Gross profit	113,951	84,918	121,495	76,775	109,577	73,146	103,229	79,273	397,139	365,225	358,005
Net income									122,645	95,702	75,565
Current assets	1,254,447				1,221,784				1,254,447	1,221,784
Current liabilities	1,027,706				992,333				1,027,706	992,333
Noncontrolling interests	824,049				724,421				824,049	724,421	611,445	538,842
Subsidiaries
Related Party Transaction [Line Items]
Sales									8,152,313	10,232,395	8,080,741
Gross profit									396,774	305,016	130,241
Income from continuing operations									233,831	148,583	34,161
Net income									219,431	144,699	32,451
Current assets	1,482,110				1,406,200				1,482,110	1,406,200
Non-current assets	558,138				508,319				558,138	508,319
Current liabilities	1,153,101				1,040,762				1,153,101	1,040,762
Non-current liabilities	381,646				244,910				381,646	244,910
Noncontrolling interests	$ 13,953				$ 20,118				$ 13,953	$ 20,118