v2.4.0.6
Derivative Financial Instruments And Hedging Activities (Schedule Of Gains (Losses) Recognized Related To Derivatives Not Designated As Hedging Instruments) (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives $ 38 $ 37 $ 63 $ 12
Capital Markets And Investment Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives 7 5 14 11
Mortgage Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives 31 32 49 1
Interest Rate Swaps [Member] | Capital Markets And Investment Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives 7 3 11 5
Interest Rate Swaps [Member] | Mortgage Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives 22 17 19 12
Interest Rate Options [Member] | Capital Markets And Investment Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives (1)   (1) 1
Interest Rate Options [Member] | Mortgage Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives 12 (1) 17 (29)
Interest Rate Futures And Forward Commitments [Member] | Capital Markets And Investment Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives (1)   (1)  
Interest Rate Futures And Forward Commitments [Member] | Mortgage Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives (3) 16 13 18
Other Contracts [Member] | Capital Markets And Investment Income [Member]
        
Derivative Instruments And Hedging Activities [Line Items]        
Amount of gain (loss) recognized in income on derivatives $ 2 $ 2 $ 5 $ 5