OTHER LIABILITIES AND DEFERRED REVENUE; OTHER REVENUES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Settlement gain			$ 1,318	$ 0
Sale of commercial building			0	1,496
Deferred revenue and other	$ 193	$ 94	367	336
Other Revenue, Net	$ 193	$ 94	$ 1,685	$ 1,832