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Employee Benefits- Fair Value of Investments (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Large-cap value | Minimum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 100 |  |
Large-cap value | Maximum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 160 |  |
International value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 8000.00% |  |
Fixed Income Investments |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 8000.00% |  |
Fourth Funds Targets Investments |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 6500.00% |  |
GSE certificates |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage | 5000.00% |  |
Large cap value | Minimum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 60 |  |
Large cap value | Maximum |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Shares | 70 |  |
Pension Plan |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 253 | $ 228 | $ 283
Pension Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 240 |  |
Pension Plan | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 12 |  |
Pension Plan | Large-cap value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 12 |  |
Pension Plan | Large-cap value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap growth |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 22 |  |
Pension Plan | Large-cap growth | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 22 |  |
Pension Plan | Large-cap growth | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap growth | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 17 |  |
Pension Plan | Large-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 17 |  |
Pension Plan | Large-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Mid-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 15 |  |
Pension Plan | Mid-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 15 |  |
Pension Plan | Mid-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Mid-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Small-cap core |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 16 |  |
Pension Plan | Small-cap core | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 16 |  |
Pension Plan | Small-cap core | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Small-cap core | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International growth |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 18 |  |
Pension Plan | International growth | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 18 |  |
Pension Plan | International growth | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International growth | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10 |  |
Pension Plan | International value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10 |  |
Pension Plan | International value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | International value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 98 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 98 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Fixed Income Funds, Intermediate Core Plus | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Company common stock |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 31 |  |
Pension Plan | Company common stock | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 31 |  |
Pension Plan | Company common stock | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Company common stock | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large cap value |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Large cap value | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Large cap value | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 13 |  |
Pension Plan | Large cap value | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0 |  |
Pension Plan | Money market |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1 |  |
Pension Plan | Money market | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1 |  |
Pension Plan | Money market | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  |  |
Pension Plan | Money market | Significant Unobservable Inputs (Level 3) |  |  |
Defined Benefit Plan, Plan Assets, Category [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 0 |  |

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