Energy Services Accounts Receivable Securitization Facility (Details) (USD $)	6 Months Ended		5 Months Ended	7 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Oct. 31, 2015	May 31, 2015
Energy Services
Accounts, Notes, Loans and Financing Receivable
Sale of trade receivables	$ 692,000,000	$ 820,700,000
Energy Services Funding Corporation
Accounts, Notes, Loans and Financing Receivable
Sale of undivided interests in its trade receivables to the commercial paper conduit	216,500,000	251,000,000
Outstanding balance of trade receivables	96,900,000	124,100,000
Outstanding balance of trade receivables sold	0	10,500,000
Forecast | Maximum
Accounts, Notes, Loans and Financing Receivable
Receivables facility			$ 75,000,000	$ 150,000,000