8. PRODUCT WARRANTIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2015	Aug. 31, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at the beginning of the period	$ 137	$ 223
Accruals for warranties issued during the period	109	32
Settlement made during the period (in cash or in kind)	(27)	(87)
Balance at the end of the period	$ 219	$ 168