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Employee Postretirement Benefits - Composition of Periodic Benefit Cost (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Retirement Benefits [Abstract] |  |  |  |
Net Periodic Benefit Cost (Income) | $ (606) | $ (1,651) | $ (1,209) | $ (3,301)
Net Amount Amortized Due to the Effect of Regulation | 749 | 356 | 1,069 | 659
Net Periodic Benefit Cost (Income) Recognized | $ 143 | $ (1,295) | $ (140) | $ (2,642)

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