Stock Options and Warrants (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Aug. 31, 2020	May 31, 2020
Stock option and warrant activity
Options and warrants outstanding, Number of Shares	131,361
Granted, Number of Shares	1,495
Exercised, Number of Shares	(45,301)
Forfeited/expired/cancelled, Number of Shares	(333)
Options and warrants outstanding, Number of Shares	87,222	131,361
Outstanding exercisable, Number of Shares	84,375
Options and warrants outstanding, Weighted Average Exercise Price	$ 0.65
Granted, Weighted Average Exercise Price	4.10
Exercised, Weighted Average Exercise Price	0.60
Forfeited/expired/cancelled, Weighted Average Exercise Price	1.23
Options and warrants outstanding, Weighted Average Exercise Price	0.70	$ 0.65
Outstanding exercisable, Weighted Average Exercise Price	$ 0.67
Options and warrants outstanding, Weighted Average Remaining Contractual Life in Years	4 years 1 month 17 days	5 years 9 months 14 days
Outstanding exercisable, Weighted Average Remaining Contractual Life in Years	3 years 11 months 26 days
Options and warrants outstanding, Aggregate Intrinsic Value	$ 232,949	$ 302,961
Outstanding exercisable, Aggregate Intrinsic Value	$ 227,520