| SHARE-BASED COMPENSATION - Unvested Class A membership interests conversion (Details) - Members' Equity, Class A | 9 Months Ended | 
|---|---|
| Sep. 30, 2021  shares | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unvested at December 31, 2020 | 200,463 | 
| Vested | (200,463) | 
| X | ||||||||||
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
 | 
| X | ||||||||||
| 
- Details 
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