EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Net income (loss)	$ 2,243	$ (735)	$ 3,656	$ (2,594)
Denominator for basic net income (loss) per share: Weighted average shares outstanding	26,871,000	23,525,000	25,684,000	23,390,000
Denominator for diluted net income (loss) per share	28,854,000	23,525,000	27,510,000	23,390,000
Basic net income (loss) per share	$ 0.08	$ (0.03)	$ 0.14	$ (0.11)
Diluted net income (loss) per share	$ 0.08	$ (0.03)	$ 0.13	$ (0.11)
Numerator [Member]
Net income (loss)	$ 2,243	$ (735)	$ 3,656	$ (2,594)
Denominator [Member]
Denominator for basic net income (loss) per share: Weighted average shares outstanding	26,871,000	23,525,000	25,684,000	23,390,000
Shares used in basic net income (loss) per share calculation	26,871,000	23,525,000	25,684,000	23,390,000
Effect of dilutive securities	1,983,000	0	1,826,000	0
Denominator for diluted net income (loss) per share	28,854,000	23,525,000	27,510,000	23,390,000
Basic net income (loss) per share	$ 0.08	$ (0.03)	$ 0.14	$ (0.11)
Diluted net income (loss) per share	$ 0.08	$ (0.03)	$ 0.13	$ (0.11)