Income Taxes - Reconciliation to Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Income Tax Disclosure [Abstract]
Federal income taxes at statutory rate	$ 28,793	$ 9,747	$ 14,715
State income taxes, net of federal income tax benefit	4,000	4,054	2,440
Impact of foreign rate differences	1,162	(2,861)	418
Impact of rate difference on impairment of goodwill	0	7,630	0
Net change in valuation allowance	578	9,070	664
Nondeductible meals & entertainment	252	592	635
Equity-based compensation	(1,012)	(1,196)	(53)
GILTI	1,911	704	241
Nondeductible transaction costs	0	90	529
Intercompany interest expense	(4,532)	(5,361)	(5,255)
Other	382	475	(295)
Total provision for income taxes	$ 31,534	$ 22,944	$ 14,039