Derivative Instruments and Hedging Activities - Effects on Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Sep. 30, 2015
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 20	$ 32
Liability derivatives	11	30
Derivatives Designated as Hedging Instruments | Interest rate swaps
Derivatives, Fair Value [Line Items]
Asset derivatives	13	19
Derivatives Designated as Hedging Instruments | Commodity forward contracts
Derivatives, Fair Value [Line Items]
Liability derivatives	7	10
Derivatives Not Designated as Hedging Instruments | Forward exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivatives	7	13
Liability derivatives	$ 4	$ 21