Provision for Income Taxes - Reconciliation of Effective Tax Rate (Details)	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate	21.00%	21.00%
US vs. foreign tax rate difference	0.50%	(0.40%)
State income tax, net of federal benefit	80.80%	16.90%
Permanent differences	(61.50%)	(14.00%)
Increase in uncertain tax position	0.70%	(1.40%)
Goodwill impairment	0.00%	(3.50%)
Change in valuation allowance	(24.30%)	(25.20%)
Income tax expense	17.20%	(6.60%)