CASH CASH EQUIVALENTS AND INVESTMENTS (Details) - USD ($) $ in Thousands	May 31, 2023	May 31, 2022
Total cash and cash equivalents	$ 30,054	$ 31,484
Cost [Member]
Cash	3,182	2,955
Total cash and cash equivalents	30,054	31,484
Total cash, cash equivalents and investments	48,074	31,564
Total cash, cash equivalents and investments	(48,074)	(31,564)
Cost [Member] | Money Market Funds
Cash equivalents	26,872	28,529
Long-term investments	150	80
Cost [Member] | U S Treasury Securities [Member]
Short-term Investments	17,870
Short-term Investments	(17,870)
Gross Unrealized Loss
Cash	0	0
Total cash and cash equivalents	0	0
Total cash, cash equivalents and investments	17	0
Total cash, cash equivalents and investments	(17)	0
Gross Unrealized Loss | Money Market Funds
Cash equivalents	0	0
Long-term investments	0	0
Gross Unrealized Loss | U S Treasury Securities [Member]
Short-term Investments	17
Short-term Investments	(17)
Estimated Fair Value [Member]
Cash	3,182	2,955
Total cash and cash equivalents	30,054	31,484
Total cash, cash equivalents and investments	48,057	31,564
Total cash, cash equivalents and investments	(48,057)	(31,564)
Estimated Fair Value [Member] | Money Market Funds
Cash equivalents	26,872	28,529
Long-term investments	150	$ 80
Estimated Fair Value [Member] | U S Treasury Securities [Member]
Short-term Investments	17,853
Short-term Investments	$ (17,853)