Income Taxes - Reconciliation to Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Income tax expense (benefit) differences to amount computed by applying federal statutory rate
Federal income taxes at statutory rate	$ 9,747	$ 14,715	$ 25,492
State income taxes, net of federal income tax benefit	4,054	2,440	1,900
Impact of foreign rate differences	(2,861)	418
Impact of rate difference on impairment of goodwill	7,630
Net change in valuation allowance	9,070	664	151
Nondeductible meals & entertainment	592	635	822
Equity-based compensation	(1,196)	(53)
GILTI	704	241
Nondeductible transaction costs	90	529	2
Net deferred benefit due to Tax Cuts and Jobs Act			(6,763)
Intercompany interest expense	(5,361)	(5,255)
Other	475	(295)	(721)
Total provision for income taxes	$ 22,944	$ 14,039	$ 20,883