STOCK-BASED COMPENSATION - Summary of Estimated Vesting of Performance Share Units (Details) - Performance Share Units - shares	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	84,478	216,083
2020 | Shares probable to be issued
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	9,040
2020 | Shares not subject to the achievement of minimum performance thresholds
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	0
2020 | Shares that could be issued if maximum performance thresholds are met
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	18,080
2019 | Shares probable to be issued
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	40,843
2019 | Shares not subject to the achievement of minimum performance thresholds
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	40,843
2019 | Shares that could be issued if maximum performance thresholds are met
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	108,522
2018 | Shares probable to be issued
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units (in shares)	34,595