For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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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.

+ References

No definition available.

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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.

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Description of timing for satisfying performance obligation in contract with customer. Includes, but is not limited to, as services are rendered, and upon shipment, delivery or completion of service.

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Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Disaggregation of Revenue [Line Items]
Description of timing			The majority of the Company's revenue arrangements are service contracts that are complete within a year or less. There are a few contracts that range in duration between 1 and 3 years.
Oncology services revenue	$ 11,786	$ 10,117	$ 23,039	$ 19,664
Revenue Benchmark \| Customer Concentration Risk \| Pharmaceutical Services And Other TOS Customer
Disaggregation of Revenue [Line Items]
Customer revenue (in Percent)	15.00%	10.00%	15.00%
Pharmacology services
Disaggregation of Revenue [Line Items]
Oncology services revenue	$ 11,143	$ 10,041	$ 21,846	19,454
Other TOS revenue
Disaggregation of Revenue [Line Items]
Oncology services revenue	643	39	1,169	60
Personalized oncology services
Disaggregation of Revenue [Line Items]
Oncology services revenue	$ 0	$ 37	$ 24	$ 150