Derivative Instruments and Hedging Activities - Effects on Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 8	$ 13
Liability derivatives	8	7
Derivatives Designated as Hedging Instruments [Member] \| Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	4
Derivatives Not Designated as Hedging Instruments [Member] \| Forward Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	4	13
Liability derivatives	$ 8	$ 7

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 55

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226000-175313

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