Annual report pursuant to Section 13 and 15(d)

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

v3.4.0.3
Changes in Accumulated Other Comprehensive Loss - Reclassifications Out of Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2016
Mar. 31, 2015
Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Income before provision for income taxes                 $ 8,730 $ 21,752 $ 14,710
Provision for income taxes                 2,599 7,017 4,565
Net income $ 520 $ 1,274 $ 1,976 $ 2,361 $ 4,165 $ 3,992 $ 4,186 $ 2,392 6,131 14,735 $ 10,145
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                   102  
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                 (1,214) (616)  
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                 (1,214) (514)  
Provision for income taxes                 (429) (182)  
Net income                 $ (785) $ (332)