Commitments and Contingencies - Additional Information (Detail) (USD $)	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	$ 324,000,000
Aggregate amount of quantifiable guarantee agreements in effect for sales of business entities, assets and third party loans	375,000,000
Potential amount of future payments under guarantees	$ 1,900,000,000

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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