Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation of Tax Rates (Detail)

v3.21.2
Income Taxes - Reconciliation of Tax Rates (Detail) - USD ($)
$ in Thousands
12 Months Ended
May 31, 2021
May 31, 2020
May 31, 2019
Income Tax Disclosure [Abstract]      
Deferred tax benefit $ 0 $ 0 $ 2,827
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
Income tax provision at statutory rate: 21.00% 21.00% 21.00%
State income taxes net 0.00% 0.00% 0.00%
Rate change 0.00% 0.00% 0.00%
Loss on debt extinguishment 0.00% 0.00% (0.50%)
Derivative gain (loss) 0.00% (1.60%) 0.60%
Valuation allowance release from asset acquisition 0.00% 0.00% 4.80%
Non-deductible debt issuance costs 0.00% (0.10%) 0.00%
Non-deductible interest on convertible notes (0.60%) (1.20%) (0.30%)
Inducement interest expense (1.50%) (1.30%) (0.10%)
Other 0.00% (0.30%) 0.00%
Credit carry forward generated (released) (0.10%) (0.10%) (3.80%)
Non-deductible loss on extinguishment of debt (2.60%) 0.00% 0.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Percent (0.60%) (0.30%) 0.00%
Effective Income Tax Rate Reconciliation Non Deductible Expense IRC 162 limitation (1.10%) (2.40%) 0.00%
Stock compensation in excess of ASC 718 1.70% 3.20% 0.00%
Non-deductible legal settlement expense (1.20%) (3.80%) 0.00%
Valuation allowance (15.00%) (13.10%) (16.90%)
Total 0.00% 0.00% 4.80%