Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Oct. 01, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Netting arrangement by counterparty with respect to certain derivative contracts in liability position have been netted against contracts in an asset position	$ 120	$ 167