PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Apr. 30, 2015
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 39,590	$ 39,098
Less accumulated depreciation	(24,043)	(23,335)
Property, plant and equipment, net	15,547	15,763
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	20,513	20,000
Furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 19,077	$ 19,098