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Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Statement of Comprehensive Income [Abstract]      
Net of related tax benefit, reclassifications of prior service benefit and actuarial loss amortization to earnings $ 0 $ 0 $ 0
Retirement expense (benefit) plans funded status adjustment, tax $ 400,000 $ 300,000 $ (200,000)