Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
ASSETS
Lease right of use assets	$ 442	$ 935
Liabilities [Abstract]
Current lease liabilities	411	541
Long-term lease liabilities	65	461
Total liabilities	$ 476	$ 1,002
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term liabilities	Other long-term liabilities
Weighted average remaining lease term	1 year 2 months 12 days	1 year 10 months 24 days
Weighted average discount rate	3.10%	3.20%
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets