Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Operating Loss Carryforwards [Line Items]
Less valuation allowance	$ 250,000	$ 0
Unrecognized tax benefits	10,259,000	9,316,000	$ 8,907,000
Unrecognized tax benefits that would impact effective tax rate	8,105,000
Increase (decrease) in unrecognized tax benefits	943,000
Accrued interest and penalties	371,000	370,000
Increase in tax expense	1,000	$ 16,000
Decrease in unrecognized tax benefits is reasonable possible	2,100,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	130,040,000
Tax Credit Carryforward, Amount	$ 1,525,000