Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Going concern thru intangibles (Detail)

v3.21.2
Summary of Significant Accounting Policies - Going concern thru intangibles (Detail) - USD ($)
 3 Months Ended
Aug. 31, 2021
Aug. 31, 2020
May 31, 2021
Accounting Policies [Abstract]      
Net loss $ 30,939,000 $ 30,832,000  
Accumulated deficit 542,653,000   $ 511,294,000
Balance in excess of federally insured limits 6,300,000   $ 33,700,000
Intangible asset impairment charges $ 0 $ 0