(Loss)/Earnings Per Share - Schedule of Computation for Earnings Per Share Types (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 9 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|
Sep. 30, 2020 |
Jun. 30, 2020 |
Mar. 31, 2020 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
|
| Earnings Per Share [Abstract] | ||||||||
| Net (loss)/income | $ (5,379) | $ (5,717) | $ (534) | $ 1,495 | $ 1,443 | $ 730 | $ (11,630) | $ 3,669 |
| Basic weighted average shares outstanding (shares) | 635 | 646 | 636 | 654 | ||||
| Dilutive effect of share-based awards (shares) | 0 | 2 | 0 | 2 | ||||
| Diluted weighted average shares outstanding (shares) | 635 | 648 | 636 | 656 | ||||
| Basic (loss)/earnings per share (USD per share) | $ (8.47) | $ 2.32 | $ (18.30) | $ 5.61 | ||||
| Diluted (loss)/earnings per share (USD per share) | $ (8.47) | $ 2.31 | $ (18.30) | $ 5.59 | ||||