Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share (Detail)

v3.20.4
Summary of Significant Accounting Policies - Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share (Detail) - shares
shares in Thousands
6 Months Ended
Nov. 30, 2020
Nov. 30, 2019
Stock options, warrants & unvested restricted stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 82,796 177,457
Convertible Debt Securities [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 12,000 10,048
Convertible Preferred Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 31,490 17,550