Equity Awards and Warrants - Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Nov. 30, 2021	May 31, 2021
Stock option and warrant activity
Options and warrants outstanding, Number of Shares	61,573,000
Granted, Number of Shares	20,151,000
Exercised, Number of Shares	(5,654,000)
Forfeited/expired/cancelled, Number of Shares	(6,443,000)
Options and warrants outstanding, Number of Shares	69,627,000	61,573,000
Outstanding exercisable, Number of Shares	59,807,000
Options and warrants outstanding, Weighted Average Exercise Price	$ 0.95
Granted, Weighted Average Exercise Price	1.97
Exercised, Weighted Average Exercise Price	0.71
Forfeited/expired/cancelled, Weighted Average Exercise Price	0.83
Options and warrants outstanding, Weighted Average Exercise Price	1.05	$ 0.95
Outstanding exercisable, Weighted Average Exercise Price	$ 0.87
Options and warrants outstanding, Weighted Average Remaining Contractual Life in Years	4 years 7 months 9 days	4 years 4 months 24 days
Outstanding exercisable, Weighted Average Remaining Contractual Life in Years	3 years 6 months 3 days
Options and warrants outstanding, Aggregate Intrinsic Value	$ 31,184	$ 68,756
Outstanding exercisable, Aggregate Intrinsic Value	$ 30,747