Quarterly report pursuant to Section 13 or 15(d)

Revenue - Narrative (Details)

v3.22.0.1
Revenue - Narrative (Details) - USD ($)
3 Months Ended 9 Months Ended
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%