Stockholders' Equity - Warrants (Details) |
3 Months Ended | 12 Months Ended | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 05, 2020
$ / shares
|
Apr. 30, 2020
shares
|
Aug. 20, 2019
investor
shares
|
Aug. 17, 2019
shares
|
Mar. 06, 2019
$ / shares
|
Mar. 05, 2019
shares
|
Nov. 08, 2018
$ / shares
shares
|
Nov. 05, 2018
$ / shares
shares
|
Jul. 31, 2020
USD ($)
|
Apr. 30, 2021
USD ($)
shares
|
Apr. 30, 2020
shares
|
Jun. 08, 2020
shares
|
Jun. 07, 2019
shares
|
Jun. 03, 2019
shares
|
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued for warrants exercised for cash | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 1,081,792 | Ìý | Ìý | Ìý | Ìý |
Modification charge for warrants exercised | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 25,966 | $ 25,966 | Ìý | Ìý | Ìý | Ìý |
Cashless exercise of warrants (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 164,929 | Ìý | Ìý | Ìý |
Number of investors | investor | Ìý | Ìý | 2 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock, shares issued (in shares) | Ìý | 21,770,520 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 25,066,297 | 21,770,520 | Ìý | Ìý | Ìý |
Senior Loans | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Granted (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | 200,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued for cashless warrant exercise (in shares) | Ìý | Ìý | Ìý | 6,271 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor | Warrant | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Cashless exercise of warrants (in shares) | Ìý | Ìý | Ìý | 13,542 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor 1 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued for cashless warrant exercise (in shares) | Ìý | Ìý | 8,970 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor 1 | Warrant | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Cashless exercise of warrants (in shares) | Ìý | Ìý | 18,818 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor 2 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued for cashless warrant exercise (in shares) | Ìý | Ìý | 42,285 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Investor 2 | Warrant | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Cashless exercise of warrants (in shares) | Ìý | Ìý | 88,710 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Former Director | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock, shares issued (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 9,806 |
Former Director | Warrant | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock, shares issued (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 21,930 |
Chief Executive Officer | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock, shares issued (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 9,597 | Ìý |
Advisory Board Member | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Granted (in shares) | Ìý | 50,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Weighted average recognition period | Ìý | 3 years | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Loan Agreements | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Warrants granted, exercise price (in dollars per share) | $ / shares | Ìý | Ìý | Ìý | Ìý | $ 6.00 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Revolving Credit Facility | Credit Facility Agreement | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Exercise price (in dollars per share) | $ / shares | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 5.85 | $ 5.85 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Class of warrant or right, number of securities called by warrants or rights (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 92,049 | 92,049 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Warrant term | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 5 years | 5 years | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Cooperman Warrants | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Decrease in exercise price of common stock purchase warrants | 5.00% | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Class of warrant or right, number of securities called by warrants or rights (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 192,049 | Ìý | Ìý |
Cooperman Warrants | Loan Agreements | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Warrants granted, exercise price (in dollars per share) | $ / shares | $ 5.70 | Ìý | Ìý | Ìý | $ 6.00 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Cooperman Warrants | Revolving Credit Facility | Credit Facility Agreement | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Exercise price (in dollars per share) | $ / shares | $ 5.56 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 5.85 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |