Energy Services Accounts Receivable Securitization Facility (Details) - USD ($)	5 Months Ended	7 Months Ended	9 Months Ended
	Oct. 31, 2015	May. 31, 2016	Jun. 30, 2015	Jun. 30, 2014
Energy Services
Accounts, Notes, Loans and Financing Receivable
Sale of trade receivables			$ 873,400,000	$ 1,073,100,000
Energy Services Funding Corporation
Accounts, Notes, Loans and Financing Receivable
Sale of undivided interests in its trade receivables to the commercial paper conduit			272,500,000	196,000,000
Outstanding balance of trade receivables			42,900,000	57,700,000
Outstanding balance of trade receivables sold			$ 20,000,000	$ 0
Forecast | Maximum
Accounts, Notes, Loans and Financing Receivable
Receivables facility	$ 75,000,000	$ 150,000,000