| Commitments and Contingencies (Details) | 9 Months Ended | 
|---|---|
| Jan. 31, 2020 | |
| Commitments and Contingencies Disclosure [Abstract] | 听 | 
| Return of unearned funds, no later than (in days) | 45 days | 
| X | ||||||||||
| 
- Definition Loss Contingency, Title IV Programs, Return of Unearned Funds, Term No definition available. 
 | 
| X | ||||||||||
| 
- References No definition available. 
 |