v2.4.0.6
Summary of Significant Accounting Policies (Details) (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Mar. 31, 2012
Private Forward Repurchase Transaction [Member]
Dec. 31, 2011
Private Forward Repurchase Transaction [Member]
Supplemental cash flow information - Noncash activities          
Transfers from trading assets to securities available for sale $ 47 $ 0 $ 854    
Transfers from (to) loans to (from) securities available for sale 2,822 3,476 (258)    
Trading assets retained from securitization of MHFS 61,599 19,815 2,993    
Capitalization of MSRs from sale of MHFS 4,089 4,570 6,287    
Transfers from MHFS to foreclosed assets 224 262 162    
Transfers from (to) loans to (from) MHFS 6,305 230 144    
Transfers from (to) loans to (from) LHFS 129 1,313 (111)    
Transfers from loans to foreclosed assets 9,315 8,699 7,604    
Changes in consolidations of variable interest entities          
Trading assets 0 155 0    
Securities available for sale 7 (7,590) 0    
Loans (599) 26,117 0    
Other assets 0 212 0    
Short-term borrowings 0 5,127 0    
Long-term debt (628) 13,613 0    
Accrued expenses and other liabilities 0 (32) 0    
Net transfer from additional paid-in capital to noncontrolling interests 0 0 2,299    
Decrease in noncontrolling interests due to deconsolidation of subsidiaries 0 440 0    
Transfer from noncontrolling interests to long term debt 0 345 0    
Consolidation of Reverse Mortgages Previously Sold [Abstract]          
Loans 5,483 0 0    
Long-term debt 5,425 0 0    
Summary Of Significant Accounting Policies Textuals [Abstract]          
Forward Contract Indexed to Issuer's Equity, Contract Amount $ 150        
Common stock repurchased, shares       6,000,000 6,000,000