Reserves for Losses (Details 1) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|---|---|---|---|
| Card Member Receivables And Related Reserves Evaluated Separately and Collectively For Impairment [Abstract] | |||
| Card Member receivables evaluated separately for impairment | $ 33 | $ 48 | $ 50 |
| Reserves on Card Member receivables evaluated separately for impairment | 20 | 35 | 38 |
| Card Member receivables evaluated collectively for impairment | 44,100 | 44,803 | 44,113 |
| Reserves on Card Member receivables evaluated collectively for impairment | $ 442 | $ 430 | $ 348 |