Equity Investees (Consolidated Financial Statements Related to Equity Investees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Genesis' share of operating earnings	$ 16,986	$ 16,444	$ 46,631	$ 47,281
Amortization of excess purchase price	(3,942)	(3,956)	(11,826)	(11,919)
Net equity in earnings	13,044	12,488	34,805	35,362
Distributions received	$ 20,180	$ 21,551	$ 60,371	$ 66,180