Employee Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Income (Detail) (Postretirement Benefits, USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Postretirement Benefits
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Net (income) loss	$ (38)	$ 16

After tax net amount of gain (loss) that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases (decreases) in other comprehensive income as they arise.

No definition available.

Name:	us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant