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