v2.4.0.6
Securities Available for Sale, Unrealized Loss Position, by Credit Rating (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses $ (1,052) $ (1,054)
Fair value 248,160 235,199
Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (1,019) (1,005)
Fair value 245,381 232,414
US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (12) 0
Fair value 6,884 7,146
US States and Political Subdivisions [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (401) (444)
Fair value 40,456 38,676
Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (408) (321)
Fair value 140,651 133,184
Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (171) (4)
Fair value 105,472 97,285
Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (42) (49)
Fair value 15,259 15,931
Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (195) (268)
Fair value 19,920 19,968
Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (60) (69)
Fair value 21,449 21,333
Collateralized loan and other debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (69) (95)
Fair value 16,663 13,188
Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (69) (76)
Fair value 19,278 18,887
Equity Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (33) (49)
Fair value 2,779 2,785
Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (25) (40)
Fair value 2,262 2,176
Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (697) (573)
Fair value 43,909 18,139
Investment Grade [Member] | Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (672) (533)
Fair value 43,288 17,485
Investment Grade [Member] | US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (12) 0
Fair value 4,369 0
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 (346) (378)
Fair value 8,556 6,839
Investment Grade [Member] | Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (209) (38)
Fair value 23,166 4,435
Investment Grade [Member] | Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (171) (4)
Fair value 20,109 2,247
Investment Grade [Member] | Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (3) (3)
Fair value 64 78
Investment Grade [Member] | Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (35) (31)
Fair value 2,993 2,110
Investment Grade [Member] | Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (23) (19)
Fair value 1,170 1,112
Investment Grade [Member] | Collateralized loan and other debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (36) (49)
Fair value 3,183 2,065
Investment Grade [Member] | Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (46) (49)
Fair value 2,844 3,034
Investment Grade [Member] | Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (25) (40)
Fair value 621 654
Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (347) (472)
Fair value 3,882 3,981
Non-investment Grade [Member] | Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (347) (472)
Fair value 3,882 3,981
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 (55) (66)
Fair value 528 532
Non-investment Grade [Member] | Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (199) (283)
Fair value 2,649 2,692
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 (39) (46)
Fair value 1,702 1,747
Non-investment Grade [Member] | Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (160) (237)
Fair value 947 945
Non-investment Grade [Member] | Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (37) (50)
Fair value 430 410
Non-investment Grade [Member] | Collateralized loan and other debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (33) (46)
Fair value 186 218
Non-investment Grade [Member] | Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (23) (27)
Fair value 89 129
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 0
Fair value $ 0 $ 0