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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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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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.

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Revenue - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
Revenue - Narrative (Details) - USD ($)	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021	Apr. 30, 2021
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 6,182,781		$ 6,182,781		$ 6,825,014
Recognition of deferred revenue			$ 5,424,788
Revenue Benchmark \| Non-US \| Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Percentage of revenues from students outside the United States	1.00%	1.00%	1.00%	1.00%