Annual report pursuant to Section 13 and 15(d)

Securities - U.S. GSE, Agency, and Treasury Securities (Details)

v2.4.0.6
Securities - U.S. GSE, Agency, and Treasury Securities (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity debt securities, Amortized Cost $ 49,481 $ 35,265
Held-to-maturity Securities, Fair Value 50,270 35,442
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity debt securities, Amortized Cost 121,522 87,898
Held-to-maturity Securities, Fair Value 123,933 89,243
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity debt securities, Amortized Cost 124,348 102,960
Held-to-maturity Securities, Fair Value 127,541 106,200
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity debt securities, Amortized Cost 22,995 26,617
Held-to-maturity Securities, Fair Value 23,502 27,129
United States Treasury Securities Exceeding Ten Percent Of Consolidated Shareholders Equity [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity debt securities, Amortized Cost 21,269 39,946
Held-to-maturity Securities, Fair Value $ 21,305 $ 39,164