Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Current expense
Federal	$ 0	$ 0	$ 0
State	310	286	113
Foreign	479	418	267
Total	789	704	380
Deferred expense
Federal	0	0	0
State	0	0	0
Foreign	0	0	0
Total	0	0	0
Provision for income taxes	$ 789	$ 704	$ 380

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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