Debt - Long-term debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
Long-term debt
Total debt	$ 190,000	$ 200,000
Less current portion	10,000	10,000
Total long-term debt, less current portion	180,000	190,000
Total long-term debt, net of unamortized debt issuance costs - term loans	$ 177,840	$ 187,512
Current period interest rate	2.60%	2.20%
Term loans
Long-term debt
Total debt	$ 190,000	$ 200,000
Less unamortized debt issuance costs - term loans	2,160	2,488
Revolving credit facility
Long-term debt
Unamortized debt issuance costs - revolving credit facility	$ 1,076	$ 1,244