CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($)  | 
12 Months Ended | |
|---|---|---|
Apr. 30, 2018  | 
Apr. 30, 2017  | 
|
| Statement of Stockholders' Equity [Abstract] | ||
| Issuance costs | $ 175,000 | $ 152,250 | 
| X | ||||||||||
- Definition The cash outflow for cost incurred directly with the issuance of an equity security. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- References No definition available. 
  |