11. CAPITAL STOCK (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Total intrinsic values of options exercised	$ 810	$ 185	$ 540
Weighted average contractual life of the options exercisable and expected to be exercisable	3 years 7 months 13 days
Exercisable options to purchase	2,422,000	2,390,000	2,189,000
Weighted average exercise prices	$ 3.21	$ 3.69	$ 1.43
RSUs vested	42,000
RSUs unvested	32,000
Market value on the date of the grant	$ 1.68	$ 2.16
Intrinsic value of RSUs, nonvested	$ 145
Intrinsic value of RSUs, vested		$ 35
2006 Stock Option Plan and 2016 Equity Incentive Plan
Authorized Shares	5,275,000
Outstanding Shares	3,105,000
Employee Stock Purchase Plan
Restricted Stock Units granted	74,000	35,000	0
Board Of Directors
Restricted Stock Units granted	83,000
Market value on the date of the grant	$ 1.86
2016 Equity Incentive Plan
Shares reserved for issuance	2,238,000
2006 Equity Incentive Plan
Shares remained available under 2006 Equity Incentive Plan	1,438,000