4. FAIR VALUE OF FINANCIAL INSTRUMENTS (Details Narrative) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Fair Value Of Financial Instruments Details Narrative
Transfers between Level 1 and Level 2 fair value measurements	$ 0	$ 0	$ 0	$ 0