SELECTED QUARTERLY DATA (UNAUDITED): (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Interest Income	$ 40,287	$ 39,539	$ 39,256	$ 41,403	$ 43,651	$ 39,595	$ 33,259	$ 32,616
Interest Expense	2,717	3,008	3,361	5,053	5,176	5,596	3,507	3,190	$ 14,139	$ 17,469	$ 9,645
NET INTEREST INCOME	37,570	36,531	35,895	36,350	38,475	33,999	29,752	29,426	146,346	131,652	116,579
Provision For Loan Losses	448	4,425	2,965	2,690	1,500	1,500	230	1,470	10,528	4,700	5,768
Net income	$ 15,739	$ 14,000	$ 11,924	$ 12,181	$ 14,364	$ 12,257	$ 12,569	$ 9,682	$ 53,844	$ 48,872	$ 46,583
BASIC AND DILUTED (in dollars per share)	$ 1.15	$ 1.02	$ 0.87	$ 0.89	$ 1.06	$ 0.93	$ 1.02	$ 0.79	$ 3.93	$ 3.80	$ 3.80