CALCULATION OF EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS													$ 146,278	$ 136,515	$ 60,776
Weighted average number of common shares outstanding
Basic weighted average shares outstanding (in shares)													34,868,434	32,784,724	32,888,007
Diluted weighted shares outstanding (in shares)													34,967,684	32,894,425	32,986,707
Earnings per common share
Basic (in dollars per share)	$ 0.96	$ 1.15	$ 1.14	$ 0.95	$ 1.10	$ 1.17	$ 1.01	$ 0.89	$ (0.41)	$ 0.76	$ 0.77	$ 0.72	$ 4.20	$ 4.16	$ 1.85
Diluted (in dollars per share)	$ 0.95	$ 1.15	$ 1.14	$ 0.95	$ 1.09	$ 1.17	$ 1.00	$ 0.89	$ (0.41)	$ 0.76	$ 0.77	$ 0.72	$ 4.18	$ 4.15	$ 1.84