Employee Benefit Plans - Healthcare Cost Trend Rates (Details) - Other Postretirement Benefits $ in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2019
USD ($)
| |
| Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates | |
| Effect of 1% increase on total service and interest cost | $ 1 |
| Effect of 1% decrease on total service and interest cost | (2) |
| Effect of 1% increase on the accumulated plan benefit obligation | 4 |
| Effect of 1% decrease on the accumulated plan benefit obligation | $ (14) |