Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance     $ 103,349  
Other comprehensive income before reclassifications     (333) $ 140
Amounts reclassified from accumulated other comprehensive loss     340 340
Total other comprehensive income $ 36 $ 256 7 480
Ending Balance 105,254   105,254  
Pension and Other Postretirement Benefits Items [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance     (8,599) (8,439)
Amounts reclassified from accumulated other comprehensive loss     340 340
Total other comprehensive income     340 340
Ending Balance (8,259) (8,099) (8,259) (8,099)
Foreign Currency Items [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance     349 5
Other comprehensive income before reclassifications     (333) 140
Total other comprehensive income     (333) 140
Ending Balance 16 145 16 145
AOCI Attributable to Parent [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance     (8,250) (8,434)
Ending Balance $ (8,243) $ (7,954) $ (8,243) $ (7,954)