v2.4.0.6
Loans and Allowance for Credit Losses, Troubled Debt Restructurings, Current Defaults (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Mar. 31, 2012
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults $ 223 $ 717
Total Commercial [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 110 517
Commercial and Industrial Loans [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 21 110
Commercial Real Estate Mortgage [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 61 252
Commercial Real Estate Construction [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 28 155
Total Consumer [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 113 200
Real estate 1-4 family first mortgage [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 83 147
Real estate 1-4 family junior lien mortgage [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 10 20
Credit Card [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults 16 27
Automobile [Member]
   
Financing Receivable, Modifications [Line Items]    
Recorded investment of defaults $ 4 $ 6