Liability Measured at Fair Value on Recurring Basis by Level within Fair Value Hierarchy (Detail) - USD ($)		May 31, 2020	May 31, 2019
Liability:
Total liability	[1]	$ 0	$ 2,407,269
warrants
Liability:
Derivative liability	[1]	0	402,132
convertible note redemption provision
Liability:
Derivative liability	[1]	0	2,005,137
Level 3
Liability:
Total liability	[1]	0	2,407,269
Level 3 | warrants
Liability:
Derivative liability	[1]	0	402,132
Level 3 | convertible note redemption provision
Liability:
Derivative liability	[1]	$ 0	$ 2,005,137

[1] The Company did not have any assets or liabilities measured at fair value using Level 1 or 2 of the fair value hierarchy as of May 31, 2020 and May 31, 2019. As of May 31, 2020, there were no longer any assets or liabilities measured at fair value using Level 3 inputs because all derivative warrants and convertible debt had been converted according to the terms of the agreements.