Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plan - Additional Information (Detail)

v3.7.0.1
Employee Benefit Plan - Additional Information (Detail) - Employee Savings Plan - USD ($)
12 Months Ended
May 31, 2017
May 31, 2016
Defined Contribution Plan Disclosure [Line Items]    
Qualified non-elective contribution 3.00%  
Qualified non-elective contribution expense $ 40,300 $ 22,000