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

v3.5.0.2
Changes in Accumulated Other Comprehensive Loss - Reclassifications Out of 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
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income before provision for income taxes $ 1,841 $ 2,941 $ 1,826 $ 6,389
Provision for income taxes 544 965 444 2,052
Net income 1,297 1,976 1,382 4,337
Reclassifications Out of Accumulated Other Comprehensive Loss [Member] | Amortization of Actuarial Loss [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income before provision for income taxes (347) (304) (695) (607)
Reclassifications Out of Accumulated Other Comprehensive Loss [Member] | Pension and Other Postretirement Benefits Items [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Provision for income taxes (123) (108) (246) (215)
Net income $ (224) $ (196) $ (449) $ (392)