Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
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, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income before provision for income taxes $ 2,005 $ (26) $ 5,030 $ 1,307
Provision for income taxes 178 (36) 880 362
Net income 1,827 10 4,150 945
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 (218) (263) (437) (526)
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 (48) (93) (97) (186)
Net income $ (170) $ (170) $ (340) $ (340)