Annual report [Section 13 and 15(d), not S-K Item 405]

Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail)

v3.25.1
Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance $ 105,566 $ 96,933 $ 96,494
Other comprehensive income (loss) before reclassifications (576) (209)  
Amounts reclassified from accumulated other comprehensive loss 602 659  
Total other comprehensive income (loss) 26 450 (992)
Ending Balance 119,577 105,566 96,933
Pension and Other Postretirement Benefits Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (6,776) (7,470)  
Other comprehensive income (loss) before reclassifications (497) 35  
Amounts reclassified from accumulated other comprehensive loss 602 659  
Total other comprehensive income (loss) 105 694  
Ending Balance (6,671) (6,776) (7,470)
Foreign Currency Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (237) 7  
Other comprehensive income (loss) before reclassifications (79) (244)  
Amounts reclassified from accumulated other comprehensive loss 0 0  
Total other comprehensive income (loss) (79) (244)  
Ending Balance (316) (237) 7
Accumulated Other Comprehensive Loss [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (7,013) (7,463) (6,471)
Ending Balance $ (6,987) $ (7,013) $ (7,463)