XML 29 R152.htm IDEA: XBRL DOCUMENT v2.4.0.6
Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) (Available-for-sale Securities [Member], Fair Value, Measurements, Recurring [Member], USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Investments, Fair Value Disclosure $ 21,953 $ 28,117
Investment in Federal Home Loan Bank Stock [Member]
   
Investments, Fair Value Disclosure 229 342
Federal Reserve Bank Stock [Member]
   
Investments, Fair Value Disclosure 402 398
Equity Funds [Member]
   
Investments, Fair Value Disclosure 69 187
Equity Securities, Other [Member] | Equity Securities, Other [Member]
   
Investments, Fair Value Disclosure $ 2 $ 2