SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Shares
Basic (in shares)	18,617	18,218	18,025
Effect of dilutive stock options (in shares)	810	659	659
Diluted (in shares)	19,427	18,877	18,684
Per Share Amount
Basic (in dollars per share)	$ 3.68	$ 1.30	$ 1.77
Effect of dilutive stock options (in dollars per share)	(0.15)	(0.05)	(0.07)
Diluted (in dollars per share)	$ 3.53	$ 1.25	$ 1.70