STOCKHOLDERS’ EQUITY (DEFICIT) - Reserve Shares of Common Stock (Details) - shares |
Jun. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Class of Stock [Line Items] | ||
| Capital shares reserved for future issuance (in shares) | 70,230,003 | 25,141,814 |
| Outstanding stock options | ||
| Class of Stock [Line Items] | ||
| Capital shares reserved for future issuance (in shares) | 12,694,680 | 8,781,615 |
| Warrants to purchase common stock | ||
| Class of Stock [Line Items] | ||
| Capital shares reserved for future issuance (in shares) | 41,260,816 | 14,040,452 |
| Shares issuable upon conversion of convertible debt | ||
| Class of Stock [Line Items] | ||
| Capital shares reserved for future issuance (in shares) | 1,547,689 | 1,217,008 |
| For possible future issuance under the Omnibus Plan | ||
| Class of Stock [Line Items] | ||
| Capital shares reserved for future issuance (in shares) | 14,726,818 | 1,102,739 |