Commitments (Details)	12 Months Ended
Apr. 30, 2017 USD ($) employee
Other Commitments
Number of other key employees covered by employment agreements \| employee	14
Minimum
Other Commitments
Compensation commitment \| $	$ 900,000

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.

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