v2.4.0.6
Securitizations and Variable Interest Entities, Significant Continuing Involvement - Unconsolidated VIEs (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Variable Interest Entity [Line Items]    
Total VIE assets $ 1,553,824 $ 1,463,183
Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 1,268,494 1,135,629
Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 49,794 61,461
Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 168,126 179,007
Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 6,940 11,240
Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 8,155 9,757
Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 10,404 9,606
Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 20,098 19,257
Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 6,641 12,191
Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 4,771 6,318
Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 10,401 18,717
Debt and equity interests [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 35,664 39,799
Maximum exposure to loss 35,664 39,799
Debt and equity interests [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,620 4,682
Maximum exposure to loss 3,620 4,682
Debt and equity interests [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 2,188 2,460
Maximum exposure to loss 2,188 2,460
Debt and equity interests [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,081 7,063
Maximum exposure to loss 7,081 7,063
Debt and equity interests [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 13 1,107
Maximum exposure to loss 13 1,107
Debt and equity interests [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,962 9,511
Maximum exposure to loss 7,962 9,511
Debt and equity interests [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,155 6,942
Maximum exposure to loss 7,155 6,942
Debt and equity interests [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 5,180 4,119
Maximum exposure to loss 5,180 4,119
Debt and equity interests [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,439 2,019
Maximum exposure to loss 1,439 2,019
Debt and equity interests [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 49 0
Maximum exposure to loss 49 0
Debt and equity interests [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 977 1,896
Maximum exposure to loss 977 1,896
Servicing assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 11,114 12,080
Maximum exposure to loss 11,114 12,080
Servicing assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 10,336 11,070
Maximum exposure to loss 10,336 11,070
Servicing assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 284 353
Maximum exposure to loss 284 353
Servicing assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 466 623
Maximum exposure to loss 466 623
Servicing assets [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Servicing assets [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 28 34
Maximum exposure to loss 28 34
Variable Interest Entity Derivatives [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 786 643
Maximum exposure to loss 1,340 2,487
Variable Interest Entity Derivatives [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Variable Interest Entity Derivatives [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 1
Maximum exposure to loss 0 1
Variable Interest Entity Derivatives [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 404 349
Maximum exposure to loss 446 538
Variable Interest Entity Derivatives [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 471 193
Maximum exposure to loss 471 874
Variable Interest Entity Derivatives [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Variable Interest Entity Derivatives [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (104) (130)
Maximum exposure to loss 104 130
Variable Interest Entity Derivatives [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Variable Interest Entity Derivatives [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1 40
Maximum exposure to loss 1 41
Variable Interest Entity Derivatives [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Variable Interest Entity Derivatives [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 14 190
Maximum exposure to loss 318 903
Other commitments and guarantees [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (3,255) (2,463)
Maximum exposure to loss 8,179 6,170
Other commitments and guarantees [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,690) (975)
Maximum exposure to loss 5,061 3,657
Other commitments and guarantees [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (53) (48)
Maximum exposure to loss 353 295
Other commitments and guarantees [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Other commitments and guarantees [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 144 0
Maximum exposure to loss 144 0
Other commitments and guarantees [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 0 0
Other commitments and guarantees [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 1,967 1,504
Other commitments and guarantees [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,657) (1,439)
Maximum exposure to loss 247 0
Other commitments and guarantees [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 261 523
Other commitments and guarantees [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 27 41
Other commitments and guarantees [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1 (1)
Maximum exposure to loss 119 150
Net assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 44,309 50,059
Maximum exposure to loss 56,297 60,536
Net assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 12,266 14,777
Maximum exposure to loss 19,017 19,409
Net assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 2,419 2,766
Maximum exposure to loss 2,825 3,109
Net assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,951 8,035
Maximum exposure to loss 7,993 8,224
Net assets [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 628 1,300
Maximum exposure to loss 628 1,981
Net assets [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,962 9,511
Maximum exposure to loss 7,962 9,511
Net assets [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,051 6,812
Maximum exposure to loss 9,226 8,576
Net assets [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,523 2,680
Maximum exposure to loss 5,427 4,119
Net assets [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,440 2,059
Maximum exposure to loss 1,701 2,583
Net assets [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 49 0
Maximum exposure to loss 76 41
Net assets [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,020 2,119
Maximum exposure to loss $ 1,442 $ 2,983