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Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]      
Defined benefit pension and other postretirement plans, tax benefit $ 509 $ (153) $ (63)