v2.4.0.6
Fair Value Measurements (Summary Of Quantitative Information About Level 3 Fair Value Measurements) (Detail) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Securities available for sale $ 27,232   $ 24,471      
Mortgage servicing rights 179 199 182 268 282 267
Loans held for sale 950   844      
Residential Non-Agency [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Securities available for sale 14   16      
Corporate And Other Debt Securities [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Securities available for sale 1,551   537      
Quoted Pricing In Illiquid Markets [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Securities Available For Sale [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Securities available for sale 14          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Spread to LIBOR [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 17.30%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Probability Of Default [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 1.00%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Loss Severity [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 49.40%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Securities Available For Sale [Member] | Weighted Average Prepayment Speed [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 12.70%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Corporate And Other Debt Securities [Member] | Securities Available For Sale [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Securities available for sale 2          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Mortgage servicing rights 179 [1]          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 18.40% [1]          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 1332.00% [1]          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 18.40%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 1332.00%          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Derivatives, Net [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Derivative assets 30          
Discounted Cash Flow [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Derivatives, Net [Member] | Pull-Through [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 75.80%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Spread to LIBOR [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 5.30%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Probability Of Default [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 0.20%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Loss Severity [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 40.40%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Securities Available For Sale [Member] | Weighted Average Prepayment Speed [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 8.80%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 5.30% [1]          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 9.50% [1]          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 5.30%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 9.50%          
Discounted Cash Flow [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Derivatives, Net [Member] | Pull-Through [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 33.30%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Spread to LIBOR [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 69.80%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Probability Of Default [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 1.20%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Loss Severity [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 100.00%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Residential Non-Agency [Member] | Securities Available For Sale [Member] | Weighted Average Prepayment Speed [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 32.30%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 30.60% [1]          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Mortgage Servicing Rights [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 32.00% [1]          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Prepayment Speeds [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 30.60%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Option-Adjusted Spread (Basis Points) [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 32.00%          
Discounted Cash Flow [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Interest Rate Options [Member] | Derivatives, Net [Member] | Pull-Through [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 99.80%          
Activity For Sales Of Similar Loans [Member] | Nonrecurring Fair Value Measurements [Member] | Loans Held For Sale [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Loans held for sale 77          
Activity For Sales Of Similar Loans [Member] | Nonrecurring Fair Value Measurements [Member] | Loans Held For Sale [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 44.60%          
Activity For Sales Of Similar Loans [Member] | Minimum [Member] | Nonrecurring Fair Value Measurements [Member] | Loans Held For Sale [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 0.00%          
Activity For Sales Of Similar Loans [Member] | Maximum [Member] | Nonrecurring Fair Value Measurements [Member] | Loans Held For Sale [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 84.00%          
Property Appraisal [Member] | Nonrecurring Fair Value Measurements [Member] | Foreclosed Property And Other Real Estate [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Foreclosed property and other real estate $ 48          
Property Appraisal [Member] | Nonrecurring Fair Value Measurements [Member] | Foreclosed Property And Other Real Estate [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 46.50%          
Property Appraisal [Member] | Minimum [Member] | Nonrecurring Fair Value Measurements [Member] | Foreclosed Property And Other Real Estate [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 4.50%          
Property Appraisal [Member] | Maximum [Member] | Nonrecurring Fair Value Measurements [Member] | Foreclosed Property And Other Real Estate [Member] | Appraisal Compatibility Adjustment Discount [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 93.30%          
Comparable Evaluated Quote [Member] | Recurring Fair Value Measurements [Member] | Other Securities [Member] | Evaluated Quote On Same Issuer/Comparable Bond [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement weighted-average percentage 99.20%          
Comparable Evaluated Quote [Member] | Recurring Fair Value Measurements [Member] | Other Securities [Member] | Comparability Adjustments [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 2.10%          
Fair value measurement weighted-average percentage 2.10%          
Comparable Evaluated Quote [Member] | Minimum [Member] | Recurring Fair Value Measurements [Member] | Other Securities [Member] | Evaluated Quote On Same Issuer/Comparable Bond [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 97.90%          
Comparable Evaluated Quote [Member] | Maximum [Member] | Recurring Fair Value Measurements [Member] | Other Securities [Member] | Evaluated Quote On Same Issuer/Comparable Bond [Member]
           
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Fair value measurement percentage 100.00%          
[1] See Note 5 for additional disclosures related to assumptions used in the fair value calculation for mortgage servicing rights.