Leases - Future Minimum Lease Payments under Noncancelable Operating Leases (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Lease Liabilities After Adoption Of ASC 842
2021	$ 775
2022	702
2023	470
2024	346
2025	20
Thereafter	0
Total operating lease payments	2,313
Less imputed interest	(126)
Total liabilities	$ 2,187
Lease Liabilities Before Adoption Of ASC 842
2020		$ 847
2021		790
2022		706
2023		433
2024		317
Thereafter		17
Future minimum lease payments due		$ 3,110

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