Leases - Narrative (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2019 |
|
| Leases [Abstract] | |||
| Operating leases | $ 783 | $ 439 | |
| 2020 | 186 | ||
| 2021 | 154 | ||
| 2022 | 108 | ||
| 2023 | 77 | ||
| 2024 | 55 | ||
| Thereafter | $ 266 | ||
| Lessee, Lease, Description [Line Items] | |||
| Operating lease, weighted-average remaining lease term | 8 years | ||
| Operating lease, weighted-average discount rate | 4.10% | ||
| Other Assets | |||
| Lessee, Lease, Description [Line Items] | |||
| Operating lease assets | $ 829 | ||