Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Antidilutive Securities (Detail)

v3.21.2
Summary of Significant Accounting Policies - Antidilutive Securities (Detail) - shares
shares in Thousands
3 Months Ended
Aug. 31, 2021
Aug. 31, 2020
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 60,141 86,704
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 7,801
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 33,858 30,325