Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Property, Plant and Equipment [Line Items]
Finance lease, depreciation and amortization expenses	$ 1,600	$ 1,900
Finance lease, depreciation and amortization expenses	$ 1,500	1,700
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other current liabilities, Other Liabilities, Noncurrent
Assets under finance lease	$ 1,000	1,000
Accumulated depreciation	11,688	10,391
Net loss on disposal of equipment	293	435
Finance lease, depreciation and amortization expense	150	146
2022 Finance Lease
Property, Plant and Equipment [Line Items]
Finance lease costs	$ 370			$ 370
Present value of minimum future obligations interest rate	3.25%
Finance lease, depreciation and amortization expense	$ 77	75
Interest on finance lease liability	3	6
2023 Finance Lease
Property, Plant and Equipment [Line Items]
Finance lease costs	$ 368		$ 368
Present value of minimum future obligations interest rate	3.50%
Finance lease, depreciation and amortization expense	$ 73	71
Interest on finance lease liability	7	9
Finance Leased Assets
Property, Plant and Equipment [Line Items]
Depreciation	150	146
Laboratory Equipment
Property, Plant and Equipment [Line Items]
Disposed of lab equipment	636	542
Accumulated depreciation	343	107
Net loss on disposal of equipment	$ 293	$ 435