Asset Retirement Obligations and Accrued Environmental Costs - Asset Retirement Obligations and Accrued Environmental Costs (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|
| Asset Retirement Obligation Disclosure [Abstract] | |||
| Asset retirement obligations | $ 8,364 | $ 8,215 | $ 7,227 |
| Accrued environmental costs | 220 | 206 | |
| Total asset retirement obligations and accrued environmental costs | 8,584 | 8,421 | |
| Asset retirement obligations and accrued environmental costs due within one year* | (370) | (332) | |
| Long-term asset retirement obligations and accrued environmental costs | $ 8,214 | $ 8,089 |