v2.4.0.6
Securitizations and Variable Interest Entities, Significant Continuing Involvement - Unconsolidated VIEs (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Variable Interest Entity [Line Items]    
Total VIE assets $ 1,564,376 $ 1,553,824
Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 1,274,961 1,268,494
Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 46,968 49,794
Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 174,917 168,126
Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 6,737 6,940
Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 8,102 8,155
Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 11,623 10,404
Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 21,047 20,098
Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 5,618 6,641
Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 4,409 4,771
Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Total VIE assets 9,994 10,401
Debt and equity interests [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 36,531 35,664
Maximum exposure to loss 36,531 35,664
Debt and equity interests [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,712 3,620
Maximum exposure to loss 3,712 3,620
Debt and equity interests [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 2,119 2,188
Maximum exposure to loss 2,119 2,188
Debt and equity interests [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,809 7,081
Maximum exposure to loss 7,809 7,081
Debt and equity interests [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 12 13
Maximum exposure to loss 12 13
Debt and equity interests [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,920 7,962
Maximum exposure to loss 7,920 7,962
Debt and equity interests [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,437 7,155
Maximum exposure to loss 7,437 7,155
Debt and equity interests [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 5,256 5,180
Maximum exposure to loss 5,256 5,180
Debt and equity interests [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,233 1,439
Maximum exposure to loss 1,233 1,439
Debt and equity interests [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 53 49
Maximum exposure to loss 53 49
Debt and equity interests [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 980 977
Maximum exposure to loss 980 977
Servicing assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 11,688 11,114
Maximum exposure to loss 11,688 11,114
Servicing assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 10,970 10,336
Maximum exposure to loss 10,970 10,336
Servicing assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 258 284
Maximum exposure to loss 258 284
Servicing assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 433 466
Maximum exposure to loss 433 466
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) 27 28
Maximum exposure to loss 27 28
Variable Interest Entity Derivatives [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 660 786
Maximum exposure to loss 1,156 1,340
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 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) 373 404
Maximum exposure to loss 426 446
Variable Interest Entity Derivatives [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 422 471
Maximum exposure to loss 422 471
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) (94) (104)
Maximum exposure to loss 94 104
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) (41) 14
Maximum exposure to loss 214 318
Other commitments and guarantees [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (3,765) (3,255)
Maximum exposure to loss 8,714 8,179
Other commitments and guarantees [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,931) (1,690)
Maximum exposure to loss 5,458 5,061
Other commitments and guarantees [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (33) (53)
Maximum exposure to loss 353 353
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) (138) 144
Maximum exposure to loss 138 144
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 1,974 1,967
Other commitments and guarantees [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (1,624) (1,657)
Maximum exposure to loss 387 247
Other commitments and guarantees [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 261 261
Other commitments and guarantees [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 0 0
Maximum exposure to loss 24 27
Other commitments and guarantees [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) (39) 1
Maximum exposure to loss 119 119
Net assets [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 45,114 44,309
Maximum exposure to loss 58,089 56,297
Net assets [Member] | Conforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 12,751 12,266
Maximum exposure to loss 20,140 19,017
Net assets [Member] | Other/Nonconforming Residential Mortgage Backed Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 2,344 2,419
Maximum exposure to loss 2,730 2,825
Net assets [Member] | Commercial mortgage securitizations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 8,615 7,951
Maximum exposure to loss 8,668 7,993
Net assets [Member] | Collateralized Debt Obligations Debt Securities [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 296 628
Maximum exposure to loss 572 628
Net assets [Member] | Collateralized Debt Obligations Loans [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,920 7,962
Maximum exposure to loss 7,920 7,962
Net assets [Member] | Asset-based finance structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 7,343 7,051
Maximum exposure to loss 9,505 9,226
Net assets [Member] | Tax Credit Structures [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 3,632 3,523
Maximum exposure to loss 5,643 5,427
Net assets [Member] | Collateralized loan obligations [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 1,233 1,440
Maximum exposure to loss 1,494 1,701
Net assets [Member] | Investment funds [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 53 49
Maximum exposure to loss 77 76
Net assets [Member] | Other securitizations and transactions [Member]
   
Variable Interest Entity [Line Items]    
Carrying value asset (liability) 927 1,020
Maximum exposure to loss $ 1,340 $ 1,442