LEASES - Lease Term and Discount Rate (Details)  | 
Jun. 30, 2020  | 
Dec. 31, 2019  | 
||
|---|---|---|---|---|
| LEASES | ||||
| Weighted-average remaining lease term, operating leases | 19 years 9 months 18 days | 20 years 2 months 12 days | ||
| Weighted-average remaining lease term, finance leases | 7 years 3 months 18 days | 7 years 9 months 18 days | ||
| Weighted-average discount rate, operating leases | [1] | 9.40% | 9.40% | |
| Weighted-average discount rate, finance leases | 4.50% | 4.50% | ||
  | ||||
| X | ||||||||||
- Definition Weighted average discount rate for finance lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Definition Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- References No definition available. 
  | 
| X | ||||||||||
- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
  |