PROPERTY AND EQUIPMENT (Summary of Property and Equipment) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024
Property and equipment
Gross property and equipment	$ 35,460	$ 35,516
Less: accumulated depreciation	(26,185)	(25,923)
Total property and equipment, net	9,275	9,593
Land and land improvements
Property and equipment
Gross property and equipment	433	433
Buildings and building improvements
Property and equipment
Gross property and equipment	9,530	9,504
Furniture, fixtures and office equipment
Property and equipment
Gross property and equipment	7,941	7,941
Leasehold Improvements
Property and equipment
Gross property and equipment	540	540
Equipment leased to customers
Property and equipment
Gross property and equipment	4,997	4,997
Plant equipment
Property and equipment
Gross property and equipment	11,060	11,142
Vehicles
Property and equipment
Gross property and equipment	$ 959	$ 959