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Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss, Net of Tax (Parenthetical) (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
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Accumulated Other Comprehensive Loss [Abstract] |  |
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans net unamortized (gain) loss, tax | $ 3,575 | $ 3,822

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- Definition Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans Net Unamortized (Gain) Loss, Tax + References No definition available. + Details
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- Definition Accumulated Other Comprehensive Loss [Abstract] + References No definition available. + Details
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