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Pension and Other Postretirement Benefit Plans - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Employer contributions to defined contribution savings plans |  | $ 215 | $ 199 | $ 175
Pension Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Accumulated benefit obligation |  | $ 18,100 | $ 19,100 |
Percentage of Company's pension investments categorized as level 3 assets |  | 4.00% | 4.00% |
Pension Benefits | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 700 | $ 788 |
Other Postretirement Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 1,040 | 1,045 | $ 947
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year |  | 70 |  |
Other Postretirement Benefits | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 0 | $ 0 |
United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Expected annual standard deviation in returns of the target portfolio which reflects both the equity allocation and the diversification benefits among the asset classes in which the portfolio invests |  | 12.00% |  |
Expected rate of return on plan assets |  | 7.75% | 7.00% | 6.70%
United States | Forecast | Subsequent Event |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Expected rate of return on plan assets | 7.70% |  |  |
United States | U.S. equities | Minimum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 25.00% |  |
United States | U.S. equities | Maximum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 40.00% |  |
United States | International equities | Minimum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 15.00% |  |
United States | International equities | Maximum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 30.00% |  |
United States | Fixed Income Investments | Minimum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 40.00% |  |
United States | Fixed Income Investments | Maximum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 50.00% |  |
United States | Cash And Other Investments | Maximum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Target allocation |  | 8.00% |  |
United States | Pension Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Accumulated benefit obligation |  | $ 10,000 | $ 10,300 |
Fair value of plan assets |  | 9,717 | 9,804 | $ 9,094
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year |  | 270 |  |
United States | Pension Benefits | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 2 | 3 | 4
International | Pension Benefits |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 9,647 | $ 9,562 | $ 8,473
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year |  | $ 180 |  |
Expected rate of return on plan assets |  | 5.20% | 5.00% | 3.70%
International | Pension Benefits | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 698 | $ 785 | $ 761

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