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Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | $ 235,612 | $ 250,674 |
Pension Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 13,137 | 13,395 |
Pension Plan | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 222,475 | 237,279 |
Pension Plan | Domestic Mutual Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 2,836 | 67 |
Pension Plan | Domestic Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 2,836 | 67 |
Pension Plan | Domestic Mutual Funds | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | U.S. government securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 10,301 | 13,328 |
Pension Plan | U.S. government securities | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 10,301 | 13,328 |
Pension Plan | U.S. government securities | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | Corporate debt securities and other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 145,908 | 146,854 |
Pension Plan | Corporate debt securities and other | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | Corporate debt securities and other | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 145,908 | 146,854 |
Pension Plan | Non-government foreign debt securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 21,843 | 20,793 |
Pension Plan | Non-government foreign debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | Non-government foreign debt securities | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 21,843 | 20,793 |
Pension Plan | Municipal bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 9,220 | 18,336 |
Pension Plan | Municipal bonds | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | Municipal bonds | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 9,220 | 18,336 |
Pension Plan | Pooled Equity Accounts |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 45,504 | 51,296 |
Pension Plan | Pooled Equity Accounts | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 0 | 0 |
Pension Plan | Pooled Equity Accounts | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 45,504 | 51,296 |
Other Postretirement Benefit Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 134,371 | 111,154 | $ 140,839
Other Postretirement Benefit Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 134,371 | 111,154 |
Other Postretirement Benefit Plan | Domestic Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | 109,575 | 89,584 |
Other Postretirement Benefit Plan | International mutual funds | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Plan Assets at Fair Value | $ 24,796 | $ 21,570 |

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