QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
QUARTERLY FINANCIAL DATA (UNAUDITED)
Interest Income	$ 42,341	$ 41,798	$ 39,202	$ 35,206	$ 34,854	$ 33,857	$ 30,870	$ 28,746	$ 158,547	$ 128,327	$ 111,110
Net Interest Income	37,671	37,400	35,511	32,287	32,041	30,990	28,198	26,372	142,869	117,601	102,725
Net income	$ 16,595	$ 11,116	$ 9,654	$ 12,073	$ 11,744	$ 11,696	$ 6,117	$ 8,766	$ 49,438	$ 38,323	$ 35,542
Earnings per Common Share
Basic	$ 0.65	$ 0.43	$ 0.38	$ 0.50	$ 0.49	$ 0.49	$ 0.27	$ 0.41	$ 1.97	$ 1.66	$ 1.64
Diluted	$ 0.64	$ 0.43	$ 0.38	$ 0.49	$ 0.48	$ 0.48	$ 0.27	$ 0.40	$ 1.94	$ 1.64	$ 1.62