v2.4.0.6
Securities Available For Sale, Major Categories (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]    
Cost $ 215,571 $ 164,329
Gross unrealized gains 10,211 11,036
Gross unrealized losses (3,169) (2,711)
Securities available for sale 222,613 172,654
Debt Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 212,642 160,071
Gross unrealized gains 9,660 10,015
Gross unrealized losses (3,106) (2,621)
Securities available for sale 219,196 167,465
US Treasury and Government [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 6,920 1,570
Gross unrealized gains 59 49
Gross unrealized losses (11) (15)
Securities available for sale 6,968 1,604
US States and Political Subdivisions [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 32,307 18,923
Gross unrealized gains 1,169 568
Gross unrealized losses (883) (837)
Securities available for sale 32,593 18,654
Mortgage Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 127,105 109,862
Gross unrealized gains 6,987 7,152
Gross unrealized losses (1,352) (1,220)
Securities available for sale 132,740 115,794
Federal agencies [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 92,279 78,578
Gross unrealized gains 4,485 3,555
Gross unrealized losses (10) (96)
Securities available for sale 96,754 82,037
Residential [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 16,997 18,294
Gross unrealized gains 1,253 2,398
Gross unrealized losses (414) (489)
Securities available for sale 17,836 20,203
Commercial [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 17,829 12,990
Gross unrealized gains 1,249 1,199
Gross unrealized losses (928) (635)
Securities available for sale 18,150 13,554
Corporate debt securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 17,921 9,015
Gross unrealized gains 769 1,301
Gross unrealized losses (286) (37)
Securities available for sale 18,404 10,279
Collateralized debt obligations [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 8,650 4,638
Gross unrealized gains 298 369
Gross unrealized losses (349) (229)
Securities available for sale 8,599 4,778
Other Debt Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 19,739 16,063
Gross unrealized gains 378 576
Gross unrealized losses (225) (283)
Securities available for sale 19,892 16,356
Equity Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 2,929 4,258
Gross unrealized gains 551 1,021
Gross unrealized losses (63) (90)
Securities available for sale 3,417 5,189
Perpetual preferred securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 2,396 3,671
Gross unrealized gains 185 250
Gross unrealized losses (54) (89)
Securities available for sale 2,527 3,832
Other equity securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Cost 533 587
Gross unrealized gains 366 771
Gross unrealized losses (9) (1)
Securities available for sale $ 890 $ 1,357