v2.4.0.8
Securitizations and Variable Interest Entities, Significant Continuing Involvement - Unconsolidated VIEs (Details) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2013
Dec. 31, 2012
Variable Interest Entity [Line Items]    
Total VIE assets $ 1,572,166 $ 1,553,824
Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 1,292,918 1,268,494
Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 43,369 49,794
Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 170,679 168,126
Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 7,084 6,940
Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 8,089 8,155
Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 10,640 10,404
Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 20,524 20,098
Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 5,719 6,641
Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 3,801 4,771
Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 9,343 10,401
Debt and equity interests [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 34,746 35,664
Maximum exposure to loss 34,746 35,664
Debt and equity interests [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,791 3,620
Maximum exposure to loss 3,791 3,620
Debt and equity interests [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,709 2,188
Maximum exposure to loss 1,709 2,188
Debt and equity interests [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,526 7,081
Maximum exposure to loss 7,526 7,081
Debt and equity interests [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 36 13
Maximum exposure to loss 36 13
Debt and equity interests [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,733 7,962
Maximum exposure to loss 7,733 7,962
Debt and equity interests [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 6,606 7,155
Maximum exposure to loss 6,606 7,155
Debt and equity interests [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 5,200 5,180
Maximum exposure to loss 5,200 5,180
Debt and equity interests [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,089 1,439
Maximum exposure to loss 1,089 1,439
Debt and equity interests [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 50 49
Maximum exposure to loss 50 49
Debt and equity interests [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,006 977
Maximum exposure to loss 1,006 977
Servicing assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 13,714 11,114
Maximum exposure to loss 13,714 11,114
Servicing assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 13,022 10,336
Maximum exposure to loss 13,022 10,336
Servicing assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 272 284
Maximum exposure to loss 272 284
Servicing assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 395 466
Maximum exposure to loss 395 466
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) 25 28
Maximum exposure to loss 25 28
Variable Interest Entity Derivatives [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 589 786
Maximum exposure to loss 1,028 1,340
Variable Interest Entity Derivatives [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (8) 0
Maximum exposure to loss 8 0
Variable Interest Entity Derivatives [Member] | Other/Nonconforming 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] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 287 404
Maximum exposure to loss 340 446
Variable Interest Entity Derivatives [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 397 471
Maximum exposure to loss 397 471
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) (91) (104)
Maximum exposure to loss 91 104
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) 0 1
Maximum exposure to loss 0 1
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) 4 14
Maximum exposure to loss 192 318
Other commitments and guarantees [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (3,763) (3,255)
Maximum exposure to loss 9,005 8,179
Other commitments and guarantees [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,918) (1,690)
Maximum exposure to loss 5,683 5,061
Other commitments and guarantees [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (41) (53)
Maximum exposure to loss 363 353
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) (130) 144
Maximum exposure to loss 130 144
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 2,005 1,967
Other commitments and guarantees [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,485) (1,657)
Maximum exposure to loss 432 247
Other commitments and guarantees [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 158 261
Other commitments and guarantees [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 43 27
Other commitments and guarantees [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (189) 1
Maximum exposure to loss 191 119
Net assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 45,286 44,309
Net assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 14,887 12,266
Net assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,940 2,419
Net assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 8,208 7,951
Net assets [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 303 628
Net assets [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,733 7,962
Net assets [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 6,515 7,051
Net assets [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,715 3,523
Net assets [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,089 1,440
Net assets [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 50 49
Net assets [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 846 1,020
Total exposure [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 58,493 56,297
Total exposure [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 22,504 19,017
Total exposure [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 2,344 2,825
Total exposure [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 8,261 7,993
Total exposure [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 563 628
Total exposure [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 7,733 7,962
Total exposure [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 8,702 9,226
Total exposure [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 5,632 5,427
Total exposure [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 1,247 1,701
Total exposure [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss 93 76
Total exposure [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Maximum exposure to loss $ 1,414 $ 1,442