FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Nov. 30, 2021	May 31, 2021
Investment securities	$ 30,582	$ 580
Money Market Fund
Investment securities	30,582	580
Level 1
Investment securities	30,582	580
Level 1 | Money Market Fund
Investment securities	30,582	580
Level 2
Investment securities	0	0
Level 2 | Money Market Fund
Investment securities	0	0
Level 3
Investment securities	0	0
Level 3 | Money Market Fund
Investment securities	$ 0	$ 0