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% |