Maximum Potential Amount of Future Fundings as the Primary Obligor for Guarantees and the Liability for Expected Future Fundings (Detail) (Primary Obligor, USD $) In Millions, unless otherwise specified	Sep. 30, 2013
Guarantor Obligations [Line Items]
Maximum Potential Amount of Future Fundings	$ 197
Liability for Guarantees	51
Debt service
Guarantor Obligations [Line Items]
Maximum Potential Amount of Future Fundings	76
Liability for Guarantees	6
Operating profit
Guarantor Obligations [Line Items]
Maximum Potential Amount of Future Fundings	105
Liability for Guarantees	44
Other
Guarantor Obligations [Line Items]
Maximum Potential Amount of Future Fundings	16
Liability for Guarantees	$ 1