Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 6	$ 7
Amortization of net loss		8
Net periodic cost	6	15
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	29	28
Amortization of net loss	2
Net periodic cost	$ 31	$ 28