Quarterly report pursuant to Section 13 or 15(d)

Employee Benefit Plan - Additional Information (Detail)

v3.8.0.1
Employee Benefit Plan - Additional Information (Detail) - Employee Savings Plan - USD ($)
3 Months Ended 9 Months Ended
Feb. 28, 2018
Feb. 28, 2017
Feb. 28, 2018
Feb. 28, 2017
Defined Contribution Plan Disclosure [Line Items]        
Qualified non-elective contribution     3.00%  
Qualified non-elective contribution expense $ 30,200 $ 10,800 $ 51,700 $ 29,500