STOCKBASED COMPENSATION (Details 7) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
STOCKBASED COMPENSATION (Details 6)
Net RSUs and PRSUs vested	240,000	96,000	207,000
Shares withheld to settle payroll taxes	178,000	62,000	9,000
Weighted average grant-date fair value of vested RSUs and PRSUs	$ 4.47	$ 3.12	$ 1.90
RSUs and PRSUs cancelled	30,000	10,000	1,000
Weighted average grant-date fair value of cancelled RSUs	$ 8.56	$ 2.93	$ 3.46
RSUs and PRSUs unvested	345,000	185,000	132,000
Weighted average grant-date fair value of unvested RSUs and PRSUs	$ 6.40	$ 3.00	$ 1.88
Intrinsic value of unvested RSUs and PRSUs (in thousands)	$ 11,392	$ 1,554	$ 297