Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
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, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income/(loss), beginning balance     $ 109,380  
Other comprehensive income before reclassifications     (148) $ (111)
Amounts reclassified from accumulated other comprehensive loss     449 392
Total other comprehensive income $ 214 $ 86 301 281
Accumulated other comprehensive income/(loss), ending balance 109,652   109,652  
Pension and Other Postretirement Benefits Items [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income/(loss), beginning balance     (10,932) (9,462)
Amounts reclassified from accumulated other comprehensive loss     449 392
Total other comprehensive income     449 392
Accumulated other comprehensive income/(loss), ending balance (10,483) (9,070) (10,483) (9,070)
Foreign Currency Items [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income/(loss), beginning balance     256 406
Other comprehensive income before reclassifications     (148) (111)
Total other comprehensive income     (148) (111)
Accumulated other comprehensive income/(loss), ending balance 108 295 108 295
AOCI Attributable to Parent        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income/(loss), beginning balance     (10,676) (9,056)
Accumulated other comprehensive income/(loss), ending balance $ (10,375) $ (8,775) $ (10,375) $ (8,775)