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Pension Plans and Other Postretirement Benefits - Additional Information (Detail) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items] |  |  |
Gain due to settlement | $ 12,000,000 | $ 0 | $ 0
Assumptions used calculating net periodic benefit sensitivity rate increase decrease discount rate | 0.25% |  |
Effect of 25 basis point increase in rate of return on pension expense | $ 8,000,000 |  |
Effect of 25 basis point decrease in rate of return on pension expense | 1,000,000 |  |
Effect of 25 basis point decrease in discount rate on benefit obligation | 48,000,000 |  |
Effect of 25 basis point increase in discount rate on benefit obligation | $ 50,000,000 |  |
Annual rate of increase in health care cost assumed for next fiscal year | 7.00% |  |
Defined Benefit Plan, ultimate health care cost trend rate | 5.00% |  |
Period for decreasing the annual rate | eight years |  |
Defined benefit pension plans | $ 828,000,000 |  |
Percentage of total assets | 26.00% |  |
Qualified benefit pension plans | $ 0 |  |
Percentage of pension plan assets that is not exceeded by investment in security of single Non-US Government of Government agency | 10.00% |  |
Defined contribution pension and retirement savings plans total expense | $ 62,000,000 | 56,000,000 | 45,000,000
Percentage of eligible employees contribution for retirement savings plan | 50.00% |  |
Percentage of employer matching contribution to employee's contribution | 100.00% |  |
Maximum employer contribution on Employee's qualified contribution | 5.00% |  |
Qualified defined contribution plans expense during the period | $ 100,000,000 | 96,000,000 | 84,000,000
Other Investments | Minimum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 5.00% |  |
Other Investments | Maximum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 60.00% |  |
Total Debt Securities | Minimum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 10.00% |  |
Total Debt Securities | Maximum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 65.00% |  |
Equity Securities | Minimum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 25.00% |  |
Equity Securities | Maximum |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Target allocations for plan assets | 60.00% |  |
Supplemental Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Projected benefit obligation | $ 132,000,000 | 146,000,000 |
Accumulated benefit obligation | 132,000,000 | 146,000,000 |
Employer contribution | 16,000,000 | 18,000,000 |
Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Gain due to settlement | 12,000,000 |  |
Decrease for settlement | 171,000,000 | 0 |
Projected benefit obligation | 2,042,000,000 | 2,369,000,000 | 2,379,000,000
Accumulated benefit obligation | 2,000,000,000.0 | 2,400,000,000 |
Employer contribution | 16,000,000 | 18,000,000 |
Settlements paid | 171,000,000 | 0 |
Other Postretirement Benefit Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Decrease for settlement | 0 | 0 |
Projected benefit obligation | 51,000,000 | 57,000,000 | $ 60,000,000
Employer contribution | 2,000,000 | 3,000,000 |
Settlements paid | $ 0 | $ 0 |

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