Equity Method Investments - Summarized financial information - NGL Energy (Details) - NGL Energy Partners LP [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Summarized income statement information
Equity Method Investment, Summarized Financial Information, Revenue	$ 2,325,440	$ 3,220,771	$ 5,010,446	$ 7,772,917
Equity Method Investment, Summarized Financial Information, Cost of Sales	2,077,160	2,933,021	4,510,660	7,244,689
Equity Method Investment, Summarized Financial Information, Operating, General and Administrative Expenses	399,373	151,793	509,145	323,857
Equity Method Investment, Summarized Financial Information, Depreciation and Amortization Expense	53,152	54,140	112,332	104,475
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ (206,985)	$ 90,942	$ (155,990)	$ 85,673