CONSOLIDATED VALUATION ACCOUNTS (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 159	$ 171	$ 178
Amounts charged to expense	0	24	39
Other Additions	0	0	0
Deductions	6	36	46
Balance at end of year	$ 153	$ 159	$ 171