Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance $ 114,110 $ 109,380 $ 116,551
Other comprehensive income before reclassifications 1,195 1,345  
Amounts reclassified from accumulated other comprehensive loss 817 897  
Total other comprehensive income 2,012 2,242 (1,620)
Amounts reclassified from accumulated other comprehensive loss to retained earnings (1,828)    
Ending Balance 103,349 114,110 109,380
Pension and Other Postretirement Benefits Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (8,439) (10,932)  
Other comprehensive income before reclassifications 851 1,596  
Amounts reclassified from accumulated other comprehensive loss 817 897  
Total other comprehensive income 1,668 2,493  
Amounts reclassified from accumulated other comprehensive loss to retained earnings (1,828)    
Ending Balance (8,599) (8,439) (10,932)
Foreign Currency Items [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance 5 256  
Other comprehensive income before reclassifications 344 (251)  
Total other comprehensive income 344 (251)  
Ending Balance 349 5 256
AOCI Attributable to Parent [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning balance (8,434) (10,676) (9,056)
Amounts reclassified from accumulated other comprehensive loss to retained earnings 1,828    
Ending Balance $ (8,250) $ (8,434) $ (10,676)