v2.4.0.6
Investment Securities (Investment) (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended 3 Months Ended 12 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Mar. 31, 2012
Debt Securities [Member]
Mar. 31, 2011
Debt Securities [Member]
Dec. 31, 2011
Debt Securities [Member]
Dec. 31, 2010
Debt Securities [Member]
Jun. 30, 2012
Domestic Corporate Debt Securities [Member]
Dec. 31, 2011
Domestic Corporate Debt Securities [Member]
Jun. 30, 2012
US States and Political Subdivisions Debt Securities [Member]
Dec. 31, 2011
US States and Political Subdivisions Debt Securities [Member]
Jun. 30, 2012
Residential Mortgage Backed Securities [Member]
Dec. 31, 2011
Residential Mortgage Backed Securities [Member]
Jun. 30, 2012
Commercial Mortgage Backed Securities [Member]
Dec. 31, 2011
Commercial Mortgage Backed Securities [Member]
Jun. 30, 2012
Asset-backed Securities [Member]
Dec. 31, 2011
Asset-backed Securities [Member]
Jun. 30, 2012
Foreign Corporate Debt Securities [Member]
Dec. 31, 2011
Foreign Corporate Debt Securities [Member]
Jun. 30, 2012
Foreign Government Debt Securities [Member]
Dec. 31, 2011
Foreign Government Debt Securities [Member]
Jun. 30, 2012
US Treasury and Government [Member]
Dec. 31, 2011
US Treasury and Government [Member]
Jun. 30, 2012
Retained Interest [Member]
Dec. 31, 2011
Retained Interest [Member]
Jun. 30, 2012
Available-for-sale Securities [Member]
Dec. 31, 2011
Available-for-sale Securities [Member]
Jun. 30, 2012
Trading Securities [Member]
Dec. 31, 2011
Trading Securities [Member]
Jun. 30, 2012
Total [Member]
Dec. 31, 2011
Total [Member]
Investment [Line Items]                                                                
Investment securities amortized cost                 $ 20,994 $ 20,748 $ 3,436 $ 3,027 $ 2,440 $ 2,711 $ 3,060 $ 2,913 $ 5,269 $ 5,102 $ 2,592 $ 2,414 $ 1,792 $ 2,488 $ 3,412 $ 3,974 $ 28 $ 25 $ 502 $ 713 $ 260 $ 241 $ 43,785 $ 44,356
Investment securities gross unrealized gains                 4,003 3,432 463 350 195 184 171 162 8 32 140 126 137 129 90 84 3 10 98 75 0 0 5,308 4,584
Investment securities gross unrealized loss                 (327) (410) (130) (143) (198) (286) (180) (247) (148) (164) (168) (207) (30) (86) 0 0 0 0 (6) (38) 0 0 (1,187) (1,581)
Investment securities estimated fair value                 24,670 23,770 3,769 3,234 2,437 2,609 3,051 2,828 5,129 4,970 2,564 2,333 1,899 2,531 3,502 4,058 31 35 594 750 260 241 47,906 47,359
Net pre-tax gains (loss) on trading securities 13 52 36 55                                                        
Marketable securities OTTI amounts 33 113 65 184                                                        
Cumulative impairments recognized in earnings associated with debt securities         434 388 558 332                                                
Marketable securities OTTI recorded in AOCI 1 59 1 66                                                        
Other than Temporary Impairment Losses, Investments 32 54 64 118                                                        
Incremental Charges On Previously Impaired Investment Securities 6 24 11 81                                                        
Other Than Temporary Impairment Related To Equity Securities 16 5 23 10                                                        
Other Than Temporary First Time Impairments Of Investment Securities Recognized In Earnings 3 19 10 20                                                        
Other Than Temporary Impairment Related To Securities Subsequently Sold 33 18 169 21                                                        
Proceeds from Sale of Available-for-sale Securities $ 2,742 $ 4,833 $ 6,504 $ 9,972