Note 4 - Income Taxes - Reconciliation of the Federal Statutory Income Tax Rate to the Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Statutory federal income tax rate expense, net of noncontrolling interest	21.00%	21.00%
State income tax, net of federal benefits	5.10%	1.90%
Permanent tax	1.46%	1.93%
Other	3.60%	(1.46%)
Other	(3.60%)	1.46%
Effective Income Tax Rate Reconciliation, Percent, Total	23.96%	26.29%
PROVISION (BENEFIT) FOR INCOME TAXES
Deferred income tax (benefit)	$ (260)	$ 1,078
Current Income Tax Expense (Benefit), Total	1,594	297
Total income tax expense	$ 1,334	$ 1,375