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

v3.8.0.1
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, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income before provision for income taxes $ (26) $ 1,841 $ 1,307 $ 1,826
Provision for income taxes (36) 544 362 444
Net income 10 1,297 945 1,382
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 (263) (347) (526) (695)
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 (93) (123) (186) (246)
Net income $ (170) $ (224) $ (340) $ (449)