XML 91 R72.htm IDEA: XBRL DOCUMENT v3.8.0.1
Loans - Credit Card: Net Charge-Offs (Detail) - Credit Card Portfolio Segment [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Loans and Leases Receivable Disclosure [Line Items]      
Net charge-offs $ 5,054 $ 3,953 $ 2,918
Percentage annualized net charge-off by average loans held for investment 4.88% 4.09%  
Percentage Annualized Net Charge-Offs by Average Loans Held for Investment, Excluding Loans Acquired Impact 4.95%    
Geographic Distribution, Domestic [Member]      
Loans and Leases Receivable Disclosure [Line Items]      
Net charge-offs $ 4,739 $ 3,681  
Percentage annualized net charge-off by average loans held for investment 4.99% 4.16%  
Percentage Annualized Net Charge-Offs by Average Loans Held for Investment, Excluding Loans Acquired Impact 5.07%    
Geographic Distribution, Foreign [Member]      
Loans and Leases Receivable Disclosure [Line Items]      
Net charge-offs $ 315 $ 272  
Percentage annualized net charge-off by average loans held for investment 3.69% 3.33%