v2.4.0.6
Securities Available for Sale, Unrealized Loss Position, by Credit Rating (Details) (USD $)
Mar. 31, 2012
Dec. 31, 2011
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses $ (1,964,000,000) $ (3,169,000,000)
Fair value 230,266,000,000 222,613,000,000
Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (1,017,000,000) (1,859,000,000)
Fair value 34,485,000,000 45,405,000,000
Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (946,000,000) (1,301,000,000)
Fair value 6,207,000,000 8,147,000,000
Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (1,920,000,000) (3,106,000,000)
Fair value 227,113,000,000 219,196,000,000
Debt Securities [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (976,000,000) (1,806,000,000)
Fair value 33,720,000,000 44,572,000,000
Debt Securities [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (944,000,000) (1,300,000,000)
Fair value 6,193,000,000 8,134,000,000
US Treasury and Government [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (7,000,000) (11,000,000)
Fair value 4,678,000,000 6,968,000,000
US Treasury and Government [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (7,000,000) (11,000,000)
Fair value 3,562,000,000 5,473,000,000
US Treasury and Government [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 0
Fair value 0 0
US States and Political Subdivisions [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (487,000,000) (883,000,000)
Fair value 34,237,000,000 32,593,000,000
US States and Political Subdivisions [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (410,000,000) (781,000,000)
Fair value 6,614,000,000 12,093,000,000
US States and Political Subdivisions [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (77,000,000) (102,000,000)
Fair value 517,000,000 756,000,000
Mortgage Backed Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (886,000,000) (1,352,000,000)
Fair value 139,151,000,000 132,740,000,000
Mortgage Backed Securities [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (275,000,000) (478,000,000)
Fair value 15,357,000,000 11,795,000,000
Mortgage Backed Securities [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (611,000,000) (874,000,000)
Fair value 4,573,000,000 5,591,000,000
Federal agencies [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (37,000,000) (10,000,000)
Fair value 102,665,000,000 96,754,000,000
Federal agencies [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (37,000,000) (10,000,000)
Fair value 10,382,000,000 3,019,000,000
Federal agencies [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses 0 0
Fair value 0 0
Residential [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (244,000,000) (414,000,000)
Fair value 17,829,000,000 17,836,000,000
Residential [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (7,000,000) (39,000,000)
Fair value 963,000,000 2,503,000,000
Residential [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (237,000,000) (375,000,000)
Fair value 3,573,000,000 4,717,000,000
Commercial [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (605,000,000) (928,000,000)
Fair value 18,657,000,000 18,150,000,000
Commercial [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (231,000,000) (429,000,000)
Fair value 4,012,000,000 6,273,000,000
Commercial [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (374,000,000) (499,000,000)
Fair value 1,000,000,000 874,000,000
Corporate debt securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (135,000,000) (286,000,000)
Fair value 20,173,000,000 18,404,000,000
Corporate debt securities [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (38,000,000) (165,000,000)
Fair value 1,705,000,000 7,156,000,000
Corporate debt securities [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (97,000,000) (121,000,000)
Fair value 694,000,000 1,118,000,000
Collateralized debt obligations [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (234,000,000) (349,000,000)
Fair value 9,163,000,000 8,599,000,000
Collateralized debt obligations [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (102,000,000) (185,000,000)
Fair value 3,131,000,000 4,597,000,000
Collateralized debt obligations [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (132,000,000) (164,000,000)
Fair value 262,000,000 284,000,000
Other Debt Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (171,000,000) (225,000,000)
Fair value 19,711,000,000 19,892,000,000
Other Debt Securities [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (144,000,000) (186,000,000)
Fair value 3,351,000,000 3,458,000,000
Other Debt Securities [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (27,000,000) (39,000,000)
Fair value 147,000,000 385,000,000
Equity Securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (44,000,000) (63,000,000)
Fair value 3,153,000,000 3,417,000,000
Perpetual preferred securities [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (43,000,000) (54,000,000)
Fair value 2,405,000,000 2,527,000,000
Perpetual preferred securities [Member] | Investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (41,000,000) (53,000,000)
Fair value 765,000,000 833,000,000
Perpetual preferred securities [Member] | Non-investment Grade [Member]
   
Securities Available for Sale in an Unrealized Loss Position by Investment Grade [Abstract]    
Gross unrealized losses (2,000,000) (1,000,000)
Fair value $ 14,000,000 $ 13,000,000