v2.4.0.6
Loans and Allowance for Credit Losses, PCI, by Delinquency Status, Commercial (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Dec. 31, 2008
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
90+ DPD and still accruing $ 23,082 $ 23,245  
Purchased Credit Impaired Loans 29,729 30,968 58,797
Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
90+ DPD and still accruing 5,800 6,000  
Total Commercial [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Purchased Credit Impaired Loans 3,502 3,977 18,704
Total Commercial [Member] | Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Current-29 DPD and still accruing 3,031 3,442  
30-89 DPD and still accruing 87 78  
90+ DPD and still accruing 384 457  
Purchased Credit Impaired Loans 3,502 3,977  
Commercial and Industrial Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Purchased Credit Impaired Loans 191 259 4,580
Commercial and Industrial Loans [Member] | Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Current-29 DPD and still accruing 187 235  
30-89 DPD and still accruing 2 1  
90+ DPD and still accruing 2 23  
Purchased Credit Impaired Loans 191 259  
Commercial Real Estate Mortgage [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Purchased Credit Impaired Loans 1,839 1,970 5,803
Commercial Real Estate Mortgage [Member] | Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Current-29 DPD and still accruing 1,703 1,804  
30-89 DPD and still accruing 57 26  
90+ DPD and still accruing 79 140  
Purchased Credit Impaired Loans 1,839 1,970  
Commercial Real Estate Construction [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Purchased Credit Impaired Loans 767 877 6,462
Commercial Real Estate Construction [Member] | Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Current-29 DPD and still accruing 608 699  
30-89 DPD and still accruing 28 51  
90+ DPD and still accruing 131 127  
Purchased Credit Impaired Loans 767 877  
Foreign Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Purchased Credit Impaired Loans 705 871 1,859
Foreign Loans [Member] | Purchased Credit-Impaired Loans [Member]
      
Purchased Credit Impaired Loans Commercial Days Past Due [Abstract]      
Current-29 DPD and still accruing 533 704  
30-89 DPD and still accruing 0 0  
90+ DPD and still accruing 172 167  
Purchased Credit Impaired Loans $ 705 $ 871