Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Oct. 31, 2023	Oct. 31, 2022	Oct. 31, 2023	Oct. 31, 2022
Disaggregation of Revenue [Line Items]
Oncology services revenue	$ 11,573	$ 14,281	$ 24,134	$ 28,026
Pharmacology services
Disaggregation of Revenue [Line Items]
Oncology services revenue	10,876	13,480	22,735	26,236
Other TOS revenue
Disaggregation of Revenue [Line Items]
Oncology services revenue	697	731	1,381	1,679
Personalized oncology services
Disaggregation of Revenue [Line Items]
Oncology services revenue	$ 0	$ 70	$ 18	$ 111

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-URI https://asc.fasb.org//1943274/2147479806/606-10-50-4

+ Details