EARNINGS PER SHARE - Computation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net income	$ 41,781	$ 41,063
Denominator:
Weighted average shares of common stock outstanding (in shares)	11,557,000	11,772,000
Effect of dilutive common stock equivalents (in shares)	81,000	109,000
Weighted average shares of common stock outstanding (in shares)	11,638,000	11,881,000
Basic earnings per share
Earnings per share - basic (in dollars per share)	$ 3.62	$ 3.49
Diluted earnings per share
Earnings per share - diluted (in dollars per share)	$ 3.59	$ 3.46