STOCK-BASED COMPENSATION - Three Year Vest Restricted Shares (Details) - Three-Year Vesting - Restricted Shares [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation
Vesting per year (as a percent)		0.33%
Granted (in shares)	43,050	43,050	23,451	20,696
Shares
Nonvested (in shares)	38,479	38,479	37,595	34,952
Granted (in shares)	43,050	43,050	23,451	20,696
Vested (in shares)		(21,220)	(18,054)	(18,053)
Forfeited (in shares)		(8,806)	(4,513)
Nonvested (in shares)		51,503	38,479	37,595
Weighted Average Fair Value
Nonvested (in dollars per share)	$ 57.82	$ 57.82	$ 60.21	$ 58.07
Granted (in dollars per share)		35.47	55.89	58.78
Vested (in dollars per share)		48.55	59.69	54.43
Forfeited (in dollars per share)		46.59	60.14
Nonvested (in dollars per share)		$ 44.88	$ 57.82	$ 60.21
Compensation cost
Unrecognized compensation cost		$ 1.4
Weighted average period of recognition of unrecognized compensation cost		1 year 8 months 12 days
Equity Award Agreements
Stock-based compensation
Number of shares attributable to Equitable Adjustment (in shares)	9,917