CONTINGENCIES (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Feb. 28, 2015	Mar. 31, 2014	Apr. 30, 2016	Apr. 30, 2015
CONTINGENCIES [Abstract]
Settlement amount		$ 1,424
Proceeds from settlement	$ 1,324
Book value of system related equipment	551
Gain on settlement	$ 773		$ 0	$ 773