SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property, Equipment, and Software (Details) - USD ($) |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
Dec. 31, 2020 |
|
| Property, Plant and Equipment [Line Items] | |||||
| General and administrative expenses | $ 25,263 | $ 306,845 | $ 62,061 | $ 487,402 | |
| Property and equipment | Minimum | |||||
| Property, Plant and Equipment [Line Items] | |||||
| Lease life or expected life | 3 years | 3 years | |||
| Property and equipment | Maximum | |||||
| Property, Plant and Equipment [Line Items] | |||||
| Lease life or expected life | 10 years | 10 years | |||
| Software | |||||
| Property, Plant and Equipment [Line Items] | |||||
| Lease life or expected life | 3 years | 3 years | |||