3. EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Earnings Per Share [Abstract]
Numerator: Net income (loss)	$ 60	$ (1,452)	$ 70	$ (2,207)
Denominator for basic net income (loss) per share: Weighted average shares outstanding (in thousands)	21,645	16,029	21,531	14,673
Shares used in basic net income (loss) per share calculation (in thousands)	21,645	16,029	21,531	14,673
Effect of dilutive securities (in thousands)	1,238	0	1,406	0
Denominator for diluted net income (loss) per share (in thousands)	22,883	16,029	22,937	14,673
Basic net income (loss) per share	$ 0	$ (0.09)	$ 0	$ (0.15)
Diluted net income (loss) per share	$ 0	$ (0.09)	$ 0	$ (0.15)