Quarterly report pursuant to Section 13 or 15(d)

Employee Benefit Plans - Components of Postretirement Benefit Income and Pension Cost (Detail)

v2.4.0.8
Employee Benefit Plans - Components of Postretirement Benefit Income and Pension Cost (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Pension Plans, Defined Benefit [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 137 $ 144 $ 273 $ 288
Interest cost 358 339 717 679
Expected return on assets (759) (682) (1,517) (1,364)
Amortization of prior service benefit 1 1 2 2
Amortization of actuarial loss 145 251 290 501
Net pension cost (income) and postretirement benefit (income) (118) 53 (235) 106
Other Postretirement Benefit Plans [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0   0  
Interest cost 8 8 16 16
Amortization of prior service benefit (27) (42) (53) (83)
Amortization of actuarial loss 10 11 20 22
Net pension cost (income) and postretirement benefit (income) $ (9) $ (23) $ (17) $ (45)