Guarantees (Details) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Type of Guarantee | ||
| Maximum potential amount of undiscounted future payments | $ 48,000 | $ 45,000 |
| Amount of related liability | 86 | 111 |
| Return and Merchant Protection [Member] | ||
| Type of Guarantee | ||
| Maximum potential amount of undiscounted future payments | 42,000 | 37,000 |
| Amount of related liability | 49 | 44 |
| Other Guarantees [Member] | ||
| Type of Guarantee | ||
| Maximum potential amount of undiscounted future payments | 6,000 | 8,000 |
| Amount of related liability | $ 37 | $ 67 |