401(K) Plan - Additional Information (Detail) - USD ($)	12 Months Ended
May 31, 2016	May 31, 2015
Compensation Related Costs [Abstract]
Profit sharing contribution	$ 0	$ 0

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