v2.4.0.6
Loans and Allowance for Credit Losses, PCI Loans Outstanding (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Dec. 31, 2008
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) $ 29,729 $ 30,968 $ 58,797
Total PCI loans (unpaid principal balance) 42,971 45,174 98,182
Total Commercial [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 3,502 3,977 18,704
Commercial and Industrial Loans [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 191 259 4,580
Commercial Real Estate Mortgage [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 1,839 1,970 5,803
Commercial Real Estate Construction [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 767 877 6,462
Foreign Loans [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 705 871 1,859
Total Consumer [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 26,227 26,991 40,093
Real estate 1-4 family first mortgage [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 26,086 26,839 39,214
Real estate 1-4 family junior lien mortgage [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) 141 152 728
Automobile [Member]
     
PCI loans [Abstract]      
Purchased Credit Impaired Loans (carrying value) $ 0 $ 0 $ 151