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)

v3.26.1
Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance $ 119,577 $ 105,566 $ 96,933
Other comprehensive income (loss) before reclassifications 491 (576)  
Amounts reclassified from accumulated other comprehensive loss 647 602  
Total other comprehensive income 1,138 26 450
Ending Balance 140,315 119,577 105,566
Pension and Other Postretirement Benefits Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (6,671) (6,776)  
Other comprehensive income (loss) before reclassifications 440 (497)  
Amounts reclassified from accumulated other comprehensive loss 647 602  
Total other comprehensive income 1,087 105  
Ending Balance (5,584) (6,671) (6,776)
Foreign Currency Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (316) (237)  
Other comprehensive income (loss) before reclassifications 51 (79)  
Amounts reclassified from accumulated other comprehensive loss 0 0  
Total other comprehensive income 51 (79)  
Ending Balance (265) (316) (237)
Accumulated Other Comprehensive Loss [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (6,987) (7,013) (7,463)
Ending Balance $ (5,849) $ (6,987) $ (7,013)