v2.4.0.6
Amount and Location in the Income Statement for Derivatives Designated as Fair Value Hedges (Detail) (Fair Value Hedging, Interest Expense, USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Interest rate contracts
   
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Gain (Loss) Recognized in Income $ 320 $ 134
Fixed-Rate Debt and Capital Leases
   
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Gain (Loss) Recognized in Income $ (320) $ (134)