Segments - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
|
| Segment Reporting Information, Profit (Loss) | ||||
| Operating revenue | $ 3,062 | $ 12,560 | $ 13,122 | $ 35,568 |
| Intersegment Sales/Other | Exchanged products | ||||
| Segment Reporting Information, Profit (Loss) | ||||
| Operating revenue | $ (249) | $ (1,143) | $ (1,144) | $ (2,953) |