EARNINGS PER SHARE - Weighted average shares (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted weighted-average shares outstanding	24,803,000	25,053,000	25,018,000
Performance-based restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted weighted-average shares outstanding	2,250	18,000	24,000
Non-performance based restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted weighted-average shares outstanding	117,790	2,400	3,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted weighted-average shares outstanding	80,000	0	0