Energy Services Accounts Receivable Securitization Facility (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Energy Services [Member]
Energy services accounts receivable securitization facility (Textual) [Abstract]
Sale of trade receivables	$ 269.0	$ 224.3
Energy Services Funding Corporation [Member]
Energy services accounts receivable securitization facility (Textual) [Abstract]
Sale of undivided interests in its trade receivables to the commercial paper conduit	92.0	79.5
Outstanding balance of trade receivables	88.5	69.3
Outstanding balance of trade receivables sold	35.5	33.0
Maximum [Member]
Energy services accounts receivable securitization facility (Textual) [Abstract]
Receivables facility	150
Minimum [Member]
Energy services accounts receivable securitization facility (Textual) [Abstract]
Receivables facility	$ 75