Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 7	$ 8	$ 22	$ 25
Amortization of net (gain) loss	8	1	23	5
Net periodic cost	15	9	45	30
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	29	36	85	105
Amortization of net (gain) loss
Net periodic cost	$ 29	$ 36	$ 85	$ 105