XML 14 R39.htm IDEA: XBRL DOCUMENT v2.4.0.6
Variable Interest Entities (Narrative) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2012
Dec. 31, 2011
Mar. 31, 2011
Variable Interest Entity [Line Items]      
Carrying amounts of assets $ 26,126 $ 26,873 $ 32,243
Carrying amounts of liabilities 24,245 25,150  
Variable Interest Entity [Member]
     
Variable Interest Entity [Line Items]      
Carrying amounts of assets 10,500 10,900  
Carrying amounts of liabilities $ 9,500 $ 9,900