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)

v3.3.0.814
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, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income before provision for income taxes $ 2,941 $ 6,272 $ 6,389 $ 9,898
Provision for income taxes 965 2,086 2,052 3,320
Net income 1,976 4,186 4,337 6,578
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   26   51
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) (607) (310)
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) (129) (607) (259)
Provision for income taxes (108) (45) (215) (91)
Net income $ (196) $ (84) $ (392) $ (168)