Employee Benefit Plans - Schedule of Components of Net Periodic Cost (Income) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Pension Benefits | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Service cost | $ 21 | $ 21 | $ 37 |
| Interest cost | 90 | 71 | 51 |
| Expected return on plan assets | (122) | (121) | (81) |
| Amortization of prior service credit | 1 | 0 | 0 |
| Amortization of net actuarial loss (gain) | 17 | 10 | 12 |
| Curtailment / settlement loss (gain) | 9 | 2 | (45) |
| Net periodic cost (income) | 16 | (17) | (26) |
| Other Postretirement Benefits | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Service cost | 1 | 2 | 2 |
| Interest cost | 4 | 5 | 6 |
| Expected return on plan assets | 0 | 0 | 0 |
| Amortization of prior service credit | (3) | (5) | (3) |
| Amortization of net actuarial loss (gain) | (7) | (2) | (2) |
| Curtailment / settlement loss (gain) | 0 | (5) | 2 |
| Net periodic cost (income) | $ (5) | $ (5) | $ 5 |