SECURITIES (Schedule of Carrying Value, Gross Unrealized Gains and Losses and Estimated Fair Value of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	$ 541,439	$ 544,851
Gross Unrealized Gains	70,094	74,982
Gross Unrealized Losses	(57)	(68)
Held-to-maturity Securities, Fair Value	611,476	619,765
U.S. government and agency securities
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	2,657	2,751
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(10)	(18)
Held-to-maturity Securities, Fair Value	2,647	2,733
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	533,733	536,767
Gross Unrealized Gains	70,091	74,978
Gross Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	603,824	611,745
Commercial
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	5,049	5,333
Gross Unrealized Gains	3	4
Gross Unrealized Losses	(47)	(50)
Held-to-maturity Securities, Fair Value	5,005	5,287
Agency | Commercial
Schedule of Held-to-maturity Securities [Line Items]
Total HTM Securities	5,049	5,333
Gross Unrealized Gains	3	4
Gross Unrealized Losses	(47)	(50)
Held-to-maturity Securities, Fair Value	5,005	5,287
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