v2.4.0.6
Securities Available for Sale, Unrealized Loss Position, by Credit Rating (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses $ (1,054) $ (3,169)
Fair value 235,199 222,613
Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (1,005) (3,106)
Fair value 232,414 219,196
US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 (11)
Fair value 7,146 6,968
US States and Political Subdivisions [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (444) (883)
Fair value 38,676 32,593
Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (321) (1,352)
Fair value 133,184 132,740
Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (4) (10)
Fair value 97,285 96,754
Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (49) (414)
Fair value 15,931 17,836
Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (268) (928)
Fair value 19,968 18,150
Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (69) (286)
Fair value 21,333 18,404
Collateralized debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (95) (349)
Fair value 13,188 8,599
Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (76) (225)
Fair value 18,887 19,892
Equity Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (49) (63)
Fair value 2,785 3,417
Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (40) (54)
Fair value 2,176 2,527
Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (573) (1,859)
Fair value 18,139 45,405
Investment Grade [Member] | Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (533) (1,806)
Fair value 17,485 44,572
Investment Grade [Member] | US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 (11)
Fair value 0 5,473
Investment Grade [Member] | US States and Political Subdivisions [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (378) (781)
Fair value 6,839 12,093
Investment Grade [Member] | Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (38) (478)
Fair value 4,435 11,795
Investment Grade [Member] | Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (4) (10)
Fair value 2,247 3,019
Investment Grade [Member] | Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (3) (39)
Fair value 78 2,503
Investment Grade [Member] | Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (31) (429)
Fair value 2,110 6,273
Investment Grade [Member] | Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (19) (165)
Fair value 1,112 7,156
Investment Grade [Member] | Collateralized debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (49) (185)
Fair value 2,065 4,597
Investment Grade [Member] | Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (49) (186)
Fair value 3,034 3,458
Investment Grade [Member] | Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (40) (53)
Fair value 654 833
Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (472) (1,301)
Fair value 3,981 8,147
Non-investment Grade [Member] | Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (472) (1,300)
Fair value 3,981 8,134
Non-investment Grade [Member] | US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 0
Fair value 0 0
Non-investment Grade [Member] | US States and Political Subdivisions [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (66) (102)
Fair value 532 756
Non-investment Grade [Member] | Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (283) (874)
Fair value 2,692 5,591
Non-investment Grade [Member] | Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 0
Fair value 0 0
Non-investment Grade [Member] | Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (46) (375)
Fair value 1,747 4,717
Non-investment Grade [Member] | Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (237) (499)
Fair value 945 874
Non-investment Grade [Member] | Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (50) (121)
Fair value 410 1,118
Non-investment Grade [Member] | Collateralized debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (46) (164)
Fair value 218 284
Non-investment Grade [Member] | Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (27) (39)
Fair value 129 385
Non-investment Grade [Member] | Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 (1)
Fair value $ 0 $ 13