CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended							9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 39,577	$ 39,700	$ 33,346	$ 37,527	$ 37,773	$ 32,424	$ 28,790	$ 112,623	$ 98,987
Basic weighted average shares outstanding	34,407,462				32,256,789			34,760,607	32,300,688
Plus unvested restricted stock	90,532				119,834			89,399	105,726
Diluted weighted shares outstanding	34,497,994				32,376,623			34,850,006	32,406,414
Earnings per common share
Basic	$ 1.15				$ 1.17			$ 3.24	$ 3.06
Diluted	$ 1.15				$ 1.17			$ 3.23	$ 3.05