INVESTMENT SECURITIES (Unrealized Losses on Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Available-for-sale securities
Less Than 12 Months, Fair Value	$ 12,759	$ 99,073
Less Than 12 Months, Unrealized Losses	116	4,411
Greater Than 12 Months, Fair Value	307,790	290,012
Greater Than 12 Months, Unrealized Losses	41,280	37,535
Total Fair Value	320,549	389,085
Total Unrealized Losses	41,396	41,946
Held-to-maturity, Debt Securities
Less Than 12 Months, Fair Value	998	266,275
Less Than 12 Months, Unrealized Losses	38	17,832
Greater Than 12 Months, Fair Value	581,650	345,643
Greater Than 12 Months, Unrealized Losses	49,390	30,219
Total Fair Value	582,648	611,918
Total Unrealized Losses	49,428	48,051
U.S. Government Treasury [Member]
Available-for-sale securities
Less Than 12 Months, Fair Value	0	983
Less Than 12 Months, Unrealized Losses	0	0
Greater Than 12 Months, Fair Value	19,318	19,189
Greater Than 12 Months, Unrealized Losses	1,727	1,928
Total Fair Value	19,318	20,172
Total Unrealized Losses	1,727	1,928
Held-to-maturity, Debt Securities
Less Than 12 Months, Fair Value	0	177,552
Less Than 12 Months, Unrealized Losses	0	11,018
Greater Than 12 Months, Fair Value	433,150	254,181
Greater Than 12 Months, Unrealized Losses	24,452	14,623
Total Fair Value	433,150	431,733
Total Unrealized Losses	24,452	25,641
U.S. Government Agency [Member]
Available-for-sale securities
Less Than 12 Months, Fair Value	11,833	63,112
Less Than 12 Months, Unrealized Losses	89	2,572
Greater Than 12 Months, Fair Value	134,243	113,004
Greater Than 12 Months, Unrealized Losses	11,239	10,291
Total Fair Value	146,076	176,116
Total Unrealized Losses	11,328	12,863
States and Political Subdivisions [Member]
Available-for-sale securities
Less Than 12 Months, Fair Value	835	1,425
Less Than 12 Months, Unrealized Losses	26	2
Greater Than 12 Months, Fair Value	37,981	38,760
Greater Than 12 Months, Unrealized Losses	6,246	6,853
Total Fair Value	38,816	40,185
Total Unrealized Losses	6,272	6,855
Mortgage-Backed Securities [Member]
Available-for-sale securities
Less Than 12 Months, Fair Value	91	6,594
Less Than 12 Months, Unrealized Losses	1	959
Greater Than 12 Months, Fair Value	60,492	60,458
Greater Than 12 Months, Unrealized Losses	13,953	10,467
Total Fair Value	60,583	67,052
Total Unrealized Losses	13,954	11,426
Held-to-maturity, Debt Securities
Less Than 12 Months, Fair Value	998	88,723
Less Than 12 Months, Unrealized Losses	38	6,814
Greater Than 12 Months, Fair Value	148,500	91,462
Greater Than 12 Months, Unrealized Losses	24,938	15,596
Total Fair Value	149,498	180,185
Total Unrealized Losses	24,976	22,410
Corporate Debt Securities [Member]
Available-for-sale securities
Less Than 12 Months, Fair Value	0	26,959
Less Than 12 Months, Unrealized Losses	0	878
Greater Than 12 Months, Fair Value	55,756	58,601
Greater Than 12 Months, Unrealized Losses	8,115	7,996
Total Fair Value	55,756	85,560
Total Unrealized Losses	$ 8,115	$ 8,874