SECURITIES (Schedule of Carrying Value, Gross Unrealized Gains and Losses and Estimated Fair Value of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	$ 547,561	$ 555,144
Gross Unrealized Gains	65,945	48,359
Gross Unrealized Losses	(77)	0
Held-to-maturity Securities, Fair Value	613,429	603,503
U.S. government and agency securities
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	2,781	2,813
Gross Unrealized Gains	0	26
Gross Unrealized Losses	(27)	0
Held-to-maturity Securities, Fair Value	2,754	2,839
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	539,187	545,148
Gross Unrealized Gains	65,944	48,274
Gross Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	605,131	593,422
Commercial
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	5,593	7,183
Gross Unrealized Gains	1	59
Gross Unrealized Losses	(50)	0
Held-to-maturity Securities, Fair Value	5,544	7,242
Agency | Commercial
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	5,593	7,183
Gross Unrealized Gains	1	59
Gross Unrealized Losses	(50)	0
Held-to-maturity Securities, Fair Value	5,544	7,242
Non-agency | Commercial
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	0	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	$ 0	$ 0