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Changes in Accumulated Other Comprehensive Loss - Reclassifications Out of Accumulated Other Comprehensive Loss by Component (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2015 | Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Income before provision for income taxes | $ 1,638 | $ 5,668 | $ 8,027 | $ 15,566
Provision for income taxes | 364 | 1,676 | 2,416 | 4,996
Net income | 1,274 | 3,992 | 5,611 | 10,570
Reclassifications Out of Accumulated Other Comprehensive Loss [Member] | Amortization of Unrecognized Prior Service Benefit [Member] |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Income before provision for income taxes |  | 25 |  | 76
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 | (304) | (155) | (911) | (465)
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] |  |  |  |
Income before provision for income taxes | (304) | (130) | (911) | (389)
Provision for income taxes | (107) | (46) | (322) | (137)
Net income | $ (197) | $ (84) | $ (589) | $ (252)

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