EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
EARNINGS PER SHARE
Weighted-average anti-dilutive stock options outstanding (in shares)	400,000	200,000	300,000	100,000
Basic earnings per share
Net income	$ 39,805	$ 47,944	$ 86,860	$ 100,794
Income attributable to unvested stock-based compensation awards	(125)	(127)	(252)	(263)
Income available to common shareholders	$ 39,680	$ 47,817	$ 86,608	$ 100,531
Weighted-average common shares outstanding - basic (in shares)	53,928,000	54,007,000	53,958,000	53,927,000
Basic earnings per share	$ 0.74	$ 0.89	$ 1.61	$ 1.86
Diluted earnings per share
Net income	$ 39,805	$ 47,944	$ 86,860	$ 100,794
Income attributable to unvested stock-based compensation awards	(125)	(127)	(252)	(263)
Income available to common shareholders	$ 39,680	$ 47,817	$ 86,608	$ 100,531
Weighted-average common shares outstanding (in shares)	53,928,000	54,007,000	53,958,000	53,927,000
Assumed exercise of stock options (in shares)	293,000	462,000	341,000	455,000
Weighted-average common shares outstanding - diluted (in shares)	54,221,000	54,469,000	54,299,000	54,382,000
Diluted earnings per share	$ 0.73	$ 0.88	$ 1.60	$ 1.85
Cash dividends declared per share (in dollars per share)	$ 0.43	$ 0.42	$ 0.86	$ 0.84
Stock Repurchase Program
Number of common shares authorized to be repurchased (in shares)					2,700,000	2,680,000
Number of common shares repurchased (in shares)			250,000