Commodity and Other Repurchase Agreements Commodity and Other Repurchase Agreements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012
Assets Sold under Agreements to Repurchase [Line Items]
Financing Receivables, net - Sales/Repurchase Agreements	$ 66.7	$ 92.5
Broker-dealers, Clearing Organizations and Counterparties [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Obligations outstanding related to commodities sold under repurchase agreements	4.1	37.0
Lenders Under Loans [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Obligations outstanding related to commodities sold under repurchase agreements	$ 56.4	$ 43.2

Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph m

-Subparagraph 1

-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(1)(i)(A)(ii))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant