PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jan. 31, 2017	Apr. 30, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 35,108	$ 35,004
Less accumulated depreciation	(24,098)	(23,007)
Property, plant and equipment, net	11,010	11,997
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	15,890	15,864
Furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 19,218	$ 19,140