v3.4.0.3
Fair Value Disclosures (Gains (Losses) Due to Changes in Instrument Specific Credit Risk) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Short-term and Long-term Borrowings | Early adoption effect    
Fair Value disclosure    
Pre-tax amount recognized in AOCI $ 138  
Short-term and Long-term Borrowings | Trading revenues    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 41 $ 125
Short-term and Long-term Borrowings | OCI    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 319 0
Securities sold under agreements to repurchase | Trading revenues    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 0 0
Securities sold under agreements to repurchase | OCI    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 4 0
Loans and other debt | Trading revenues    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk (100) 77
Loans and other debt | OCI    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 0 0
Lending Commitments | Trading revenues    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk 1 9
Lending Commitments | OCI    
Fair Value disclosure    
Gains (losses) due to changes in instrument specific credit risk $ 0 $ 0