Derivatives - Fair Value Hedges - IS Location (Details) - Fair value hedges - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Derivatives in Fair Value Hedging Relationships | ||
| Gain (Loss) on Derivative Recognized in Income | $ (5) | $ (9) |
| Gain (Loss) on Hedged Item Recognized in Income | 5 | 9 |
| Interest rate swap contracts | Interest expense. | ||
| Derivatives in Fair Value Hedging Relationships | ||
| Gain (Loss) on Derivative Recognized in Income | (5) | (9) |
| Gain (Loss) on Hedged Item Recognized in Income | $ 5 | $ 9 |