NATURE OF OPERATIONS - Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accounting Policies [Abstract]
Net income	$ 7,576	$ 12,010
Weighted average common shares outstanding - basic (in shares)	55,611,827	56,519,809
Add: Dilutive effects of assumed vesting of restricted stock (in shares)	113,271	202,887
Weighted average common shares outstanding - diluted (in shares)	55,725,098	56,722,696
Basic earnings per common share (in usd per share)	$ 0.14	$ 0.21
Diluted earnings per common share (in usd per share)	$ 0.14	$ 0.21
Anti-dilutive shares not included in calculation of diluted earnings per share (in shares)	17,313	13,981