Commitments (Details) $ in Thousands	12 Months Ended
Apr. 30, 2020 USD ($) employee
Other Commitments
Number of other key employees covered by employment agreements \| employee	21
Minimum
Other Commitments
Compensation commitment \| $	$ 950

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.

No definition available.

Name:	us-gaap_OtherCommitmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration