Related Party Transactions (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transactions [Abstract]
Revenues	$ 1,601,778	$ 1,646,697	$ 4,603,808	$ 4,676,583
Gross profit	58,826	50,141	155,568	127,963
Income from continuing operations	9,501	18,965	15,507	1,428
Net income (loss)	7,918	17,217	14,878	(2,924)
Net income (loss) attributable to companies	$ 9,545	$ 17,752	$ 15,781	$ (1,347)