Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Apr. 30, 2022	Apr. 30, 2021
Tax Credit Carryforward [Line Items]
Valuation allowance	$ 5,122	$ 4,914
Foreign Tax Authority [Member]
Tax Credit Carryforward [Line Items]
Valuation allowance	200
Gross amount of state tax credit carryforwards	1,900	1,700
State [Member]
Tax Credit Carryforward [Line Items]
Gross amount of state tax credit carryforwards	3,700	3,800
Net deferred tax assets related to tax credit carryforwards	400	500
State [Member] | Other Liabilities [Member]
Tax Credit Carryforward [Line Items]
Net deferred tax assets related to tax credit carryforwards	$ 400	$ 500