Liability Measured at Fair Value on Recurring Basis by Level within Fair Value Hierarchy (Detail) - USD ($)		Nov. 30, 2019	May 31, 2019
Liability:
Total liability	[1]	$ 1,578,770	$ 2,407,269
warrants
Liability:
Derivative liability	[1]	122,372	402,132
convertible note redemption provision
Liability:
Derivative liability	[1]	1,456,398	2,005,137
Level 3
Liability:
Total liability	[1]	1,578,770	2,407,269
Level 3 | warrants
Liability:
Derivative liability	[1]	122,372	402,132
Level 3 | convertible note redemption provision
Liability:
Derivative liability	[1]	$ 1,456,398	$ 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 November 30, 2019 and May 31, 2019.