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Employee Benefits (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Target allocation and pension plan asset allocation |  |  |
Contributions made to defined benefit pension plans | $ 13 | $ 1 |
Estimated fair value of plan assets | 171 | 182 | $ 227
Reconciliation of benefit obligation: |  |  |
Benefit obligation at beginning of year | 276 | 362 |
Service cost | 6 | 9 | 10
Interest cost | 13 | 10 | 9
Actuarial gains | 1 | (97) |
Plan settlements | (46) |  |
Benefits paid | (8) | (8) |
Benefit obligation at end of year | 242 | 276 | 362
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 182 | 227 |
Actual return on plan assets | 30 | (38) |
Employer contributions | 13 | 1 |
Plan settlements | (46) |  |
Benefits paid | (8) | (8) |
Fair value of plan assets at end of year | 171 | 182 | 227
Funded status | (71) | (94) |
Components of net periodic benefit cost: |  |  |
Service cost | 6 | 9 | 10
Interest cost | 13 | 10 | 9
Expected return on plan assets | (11) | (14) | (12)
Amortization |  | 6 | 9
Settlement loss recognized | 1 |  | 6
Net periodic benefit cost | 9 | 11 | 22
Amounts not reflected in net periodic benefit cost and included in accumulated other comprehensive loss (AOCL) before taxes |  |  |
Total accumulated other comprehensive loss | 2 | 21 |
Assets exceed accumulated benefits |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 122 | 126 |
Reconciliation of benefit obligation: |  |  |
Benefit obligation at beginning of year | 129 |  |
Service cost | 3 |  |
Interest cost | 7 |  |
Actuarial gains | (1) |  |
Plan settlements | (21) |  |
Benefits paid | (4) |  |
Benefit obligation at end of year | 113 | 129 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 126 |  |
Actual return on plan assets | 21 |  |
Plan settlements | (21) |  |
Benefits paid | (4) |  |
Fair value of plan assets at end of year | 122 | 126 |
Funded status | 9 |  |
Components of net periodic benefit cost: |  |  |
Service cost | 3 |  |
Interest cost | 7 |  |
Accumulated benefits exceed assets |  |  |
Target allocation and pension plan asset allocation |  |  |
Contributions made to defined benefit pension plans | 13 |  |
Estimated fair value of plan assets | 49 | 56 |
Reconciliation of benefit obligation: |  |  |
Benefit obligation at beginning of year | 147 |  |
Service cost | 3 |  |
Interest cost | 6 |  |
Actuarial gains | 2 |  |
Plan settlements | (25) |  |
Benefits paid | (4) |  |
Benefit obligation at end of year | 129 | 147 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 56 |  |
Actual return on plan assets | 9 |  |
Employer contributions | 13 |  |
Plan settlements | (25) |  |
Benefits paid | (4) |  |
Fair value of plan assets at end of year | 49 | 56 |
Funded status | (80) |  |
Components of net periodic benefit cost: |  |  |
Service cost | 3 |  |
Interest cost | 6 |  |
Defined benefit pension plan |  |  |
Target allocation and pension plan asset allocation |  |  |
Contributions made to defined benefit pension plans | 0 | 0 | $ 0
Estimated fair value of plan assets | $ 171 | $ 182 |
Weighted-average assumptions |  |  |
Discount rate used to determine obligations (as a percent) | 5.26% | 5.38% | 2.78%
Discount rate used to determine net periodic benefit cost (as a percent) | 5.38% | 2.78% | 2.39%
Expected return on plan assets (as a percent) | 6.50% | 6.25% | 6.25%
Long-term rate of increase in compensation levels (as a percent) | 3.80% | 4.00% | 4.00%
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | $ 182 |  |
Employer contributions | 0 | $ 0 | $ 0
Fair value of plan assets at end of year | 171 | 182 |
Expected future benefit payments |  |  |
2024 | 29 |  |
2025 | 10 |  |
2026 | 15 |  |
2027 | 12 |  |
2028 | 15 |  |
Next five years after year five | 72 |  |
Accumulated benefit obligation | 216 | 247 |
Accumulated benefit obligation for defined benefit pension plans in excess of plan assets | 118 | 130 |
Defined benefit pension plan | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 171 | 182 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 182 |  |
Fair value of plan assets at end of year | $ 171 | 182 |
Defined benefit pension plan | Equity Securities |  |  |
Target allocation and pension plan asset allocation |  |  |
Target Allocations (as a percent) | 80.00% |  |
Defined benefit pension plan | Domestic equity securities |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | $ 81 | 84 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 84 |  |
Fair value of plan assets at end of year | 81 | 84 |
Defined benefit pension plan | Domestic equity securities | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 81 | 84 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 84 |  |
Fair value of plan assets at end of year | 81 | 84 |
Defined benefit pension plan | Foreign equity securities |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 51 | 60 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 60 |  |
Fair value of plan assets at end of year | 51 | 60 |
Defined benefit pension plan | Foreign equity securities | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 51 | 60 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 60 |  |
Fair value of plan assets at end of year | $ 51 | 60 |
Defined benefit pension plan | Fixed income |  |  |
Target allocation and pension plan asset allocation |  |  |
Target Allocations (as a percent) | 20.00% |  |
Estimated fair value of plan assets | $ 26 | 26 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 26 |  |
Fair value of plan assets at end of year | 26 | 26 |
Defined benefit pension plan | Fixed income | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 26 | 26 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 26 |  |
Fair value of plan assets at end of year | 26 | 26 |
Defined benefit pension plan | International fixed income mutual funds |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 11 | 11 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 11 |  |
Fair value of plan assets at end of year | 11 | 11 |
Defined benefit pension plan | International fixed income mutual funds | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 11 | 11 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 11 |  |
Fair value of plan assets at end of year | 11 | 11 |
Defined benefit pension plan | Money market funds |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 2 | 1 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 1 |  |
Fair value of plan assets at end of year | 2 | 1 |
Defined benefit pension plan | Money market funds | Level 1 |  |  |
Target allocation and pension plan asset allocation |  |  |
Estimated fair value of plan assets | 2 | 1 |
Reconciliation of fair value of plan assets: |  |  |
Fair value of plan assets at beginning of year | 1 |  |
Fair value of plan assets at end of year | 2 | $ 1 |
Group annuity contract |  |  |
Reconciliation of benefit obligation: |  |  |
Plan settlements | (34) |  |
Expected future benefit payments |  |  |
Decrease in related assets due to purchase of group annuity buy-out contract | $ 34 |  |

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- Definition Amount of decrease in related assets due to an agreement with an insurance company to purchase a group annuity buy-out contract for a select group of retirees. + References No definition available. + Details
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- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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