EARNINGS PER SHARE - Schedule of computation of earnings per common share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net income per share calculations for basic and diluted methods
Net income	$ 122,565	$ 128,311	$ 123,449
Shares:
Weighted average number of common shares outstanding, basic (in shares)	55,432,322	55,387,073	55,369,476
Weighted average number of common shares outstanding, diluted (in shares)	56,256,148	56,137,164	56,008,805
Basic earnings per common share (in dollars per share)	$ 2.21	$ 2.32	$ 2.23
Diluted earnings per common share (in dollars per share)	$ 2.18	$ 2.29	$ 2.20
Options
Shares:
Dilutive effect of common stock equivalents (in shares)	0	1,632	1,639
Warrants
Shares:
Dilutive effect of common stock equivalents (in shares)	324	1,753	1,753
RSU awards
Shares:
Dilutive effect of common stock equivalents (in shares)	647,217	665,998	615,759
PSU awards
Shares:
Dilutive effect of common stock equivalents (in shares)	151,190	58,206	5,429
DSU awards
Shares:
Dilutive effect of common stock equivalents (in shares)	18,154	15,532	10,641
2021 ESPP
Shares:
Dilutive effect of common stock equivalents (in shares)	6,941	6,970	4,108