Related Party Transactions (Details 1) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Sales	$ 1,183,473	$ 909,093	$ 1,187,704	$ 918,225	$ 1,271,768	$ 952,927	$ 1,312,082	$ 1,003,294	$ 4,198,495	$ 4,540,071	$ 5,604,574
Gross profit	99,162	$ 85,190	$ 108,173	$ 83,313	113,951	$ 84,918	$ 121,495	$ 76,775	375,838	397,139	365,225
Net income (loss)									(11,322)	122,645	95,702
Current assets	1,129,522				1,254,447				1,129,522	1,254,447
Current liabilities	888,037				1,027,706				888,037	1,027,706
Noncontrolling interests	783,739				824,049				783,739	824,049	724,421	$ 611,445
Subsidiaries
Related Party Transaction [Line Items]
Sales									6,868,257	8,152,313	10,232,395
Gross profit									250,847	396,774	305,016
Income from continuing operations									85,220	233,831	148,583
Net income (loss)									81,368	219,431	144,699
Current assets	1,236,171				1,482,110				1,236,171	1,482,110	1,406,200
Non-current assets	500,637				558,138				500,637	558,138	508,319
Current liabilities	796,816				1,153,101				796,816	1,153,101	1,040,762
Non-current liabilities	342,075				381,646				342,075	381,646	244,910
Noncontrolling interests	$ 11,716				$ 13,953				$ 11,716	$ 13,953	$ 20,118