Retirement Savings Plan - Additional Information (Detail) (USD $)	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Employer contribution	$ 443,000	$ 338,000	$ 372,000

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration