Stockholders' Equity - Preferred Stock and Common Stock (Details) |
1 Months Ended | 3 Months Ended | 12 Months Ended | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 14, 2020
USD ($)
$ / shares
shares
|
Sep. 14, 2020
USD ($)
d
$ / shares
|
Sep. 14, 2020
USD ($)
day
$ / shares
|
Aug. 31, 2020
USD ($)
|
Jan. 22, 2020
USD ($)
d
$ / shares
shares
|
Nov. 30, 2019
USD ($)
shares
|
Apr. 29, 2015
USD ($)
|
Dec. 31, 2019
USD ($)
shares
|
Jan. 31, 2021
$ / shares
|
Jul. 31, 2020
shares
|
Apr. 30, 2021
USD ($)
shares
|
Apr. 30, 2020
USD ($)
shares
|
Jun. 28, 2019
shares
|
Jun. 27, 2019
shares
|
|
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Preferred stock, shares authorized (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 1,000,000 | 1,000,000 | 1,000,000 | 10,000,000 |
Preferred stock, shares issued (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 0 | 0 | Ìý | Ìý |
Preferred stock, shares outstanding (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 0 | 0 | Ìý | Ìý |
Common stock, shares authorized (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 40,000,000 | 40,000,000 | 40,000,000 | 250,000,000 |
Common stock issued for stock options exercised for cash (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 52,778 | 363,334 | Ìý | Ìý |
Common stock issued for stock options exercised for cash | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 2,669,247 | $ 962,650 | Ìý | Ìý |
Number of shares of common stock surrendered (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 155,486 | Ìý | Ìý | Ìý |
Common stock issued for warrants exercised for cash | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 1,081,792 | Ìý | Ìý | Ìý |
Common stock issued for cashless warrant exercise (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 76,929 | Ìý | Ìý |
Cashless exercise of warrants (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 164,929 | Ìý | Ìý |
Common stock issued for services | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 19,900 | Ìý | Ìý | Ìý |
Proceeds from sale of common stock net of underwriter costs | $ | Ìý | Ìý | Ìý | Ìý | $ 17,267,250 | Ìý | $ 101,502 | Ìý | Ìý | Ìý | $ 0 | $ 16,044,879 | Ìý | Ìý |
Common stock issued in equity raise (in dollars per share) | $ / shares | Ìý | Ìý | Ìý | Ìý | $ 7.15 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Stock issued during period, value, new issues | $ | Ìý | Ìý | Ìý | Ìý | $ 16,044,879 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Convertible Notes | Convertible Notes Payable | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Average closing price of common stock (in dollars per share) | $ / shares | $ 10.725 | $ 10.725 | $ 10.725 | Ìý | $ 10.725 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Consecutive trading day period | Ìý | 20 | 20 | Ìý | 20 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Debt instrument issued | $ | $ 10,000,000 | $ 10,000,000 | $ 10,000,000 | Ìý | $ 5,000,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Debt instrument, convertible, conversion price (in dollars per share) | $ / shares | $ 7.15 | $ 7.15 | $ 7.15 | Ìý | $ 7.15 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Convertible Notes | Convertible Notes Payable | Common Stock | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Debt conversion, converted instrument, shares issued (in shares) | 1,398,602 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Preferred Stock | Maximum | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Preferred stock, shares authorized (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 1,000,000 | Ìý | Ìý | Ìý |
Common Stock | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued for stock options exercised for cash (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 1,389,463 | 277,678 | Ìý | Ìý |
Common stock issued for stock options exercised for cash | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 1,389 | $ 278 | Ìý | Ìý |
Common stock issued for vested restricted stock units (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 295,557 | 0 | Ìý | Ìý |
Common stock issued for cashless exercise of stock options (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 34,773 | 190,559 | Ìý | Ìý |
Common stock issued for warrants exercised for cash (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 192,049 | 192,049 | Ìý | Ìý | Ìý |
Common stock issued for warrants exercised for cash | $ | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 192 | Ìý | Ìý | Ìý |
Common stock issued for cashless warrant exercise (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 76,929 | Ìý | Ìý |
Common stock issued for services (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | 25,000 | Ìý | Ìý | Ìý | Ìý | 2,000 | Ìý | Ìý | Ìý |
Common stock issued for services | $ | Ìý | Ìý | Ìý | Ìý | Ìý | $ 177,500 | Ìý | Ìý | Ìý | Ìý | $ 2 | Ìý | Ìý | Ìý |
Common stock issued (in shares) | Ìý | Ìý | Ìý | Ìý | 2,415,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common Stock | Former Director | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Grant date share price (in dollars per share) | $ / shares | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 9.95 | Ìý | Ìý | Ìý | Ìý | Ìý |
Common Stock | Chief Financial Officer | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock issued (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | 15,000 | Ìý | 15,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Stock issued during period, value, new issues | $ | Ìý | Ìý | Ìý | Ìý | Ìý | $ 103,350 | Ìý | $ 103,350 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Equity Distribution Agreement | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Common stock, capital shares reserved for future issuance, value | $ | Ìý | Ìý | Ìý | $ 12,309,750 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Number of shares sold (in shares) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 449,632 | Ìý | Ìý | Ìý |
Sale of stock, gross proceeds (as a percent) | Ìý | Ìý | Ìý | 3.00% | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Reimbursement expenses | $ | Ìý | Ìý | Ìý | $ 50,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Total expenses for offering | $ | Ìý | Ìý | Ìý | $ 50,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Over-Allotment Option | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Schedule Of Stockholders Equity [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Sale of stock, number of shares issued in transaction | Ìý | Ìý | Ìý | Ìý | 315,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |