Equity Method Investments - Summarized financial information - NGL Energy (Details) - NGL Energy Partners LP [Member] - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Summarized income statement information
Equity Method Investment, Summarized Financial Information, Revenue	$ 2,685,006	$ 4,552,146
Equity Method Investment, Summarized Financial Information, Cost of Sales	2,433,500	4,311,668
Equity Method Investment, Summarized Financial Information, Operating, General and Administrative Expenses	131,146	172,064
Equity Method Investment, Summarized Financial Information, Depreciation and Amortization Expense	59,180	50,335
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ 29,621	$ (5,269)