INVESTMENT SECURITIES (Schedule of Securities with Unrealized Losses) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Held-to-maturity Securities
Number of securities of one issuer | item	0	0
Impairment loss	$ 0	$ 0
Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	23,378	35,528
Less than 12 Months, Unrealized/Unrecognized Losses	(442)	(2,379)
12 months or more, Estimated Fair Value	390,315	387,125
12 months or more, Unrealized/Unrecognized Losses	(87,218)	(86,828)
Total, Estimated Fair Value	413,693	422,653
Total, Unrealized/Unrecognized Losses	(87,660)	(89,207)
Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	49,536	194,848
Less than 12 Months, Unrealized/Unrecognized Losses	(2,863)	(23,599)
12 months or more, Estimated Fair Value	368,026	242,442
12 months or more, Unrealized/Unrecognized Losses	(70,324)	(49,536)
Total, Estimated Fair Value	417,562	437,290
Total, Unrealized Losses	(73,187)	(73,135)
U.S. Government agency securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 Months, Unrealized/Unrecognized Losses	0	0
12 months or more, Estimated Fair Value	59,763	59,372
12 months or more, Unrealized/Unrecognized Losses	(8,234)	(8,624)
Total, Estimated Fair Value	59,763	59,372
Total, Unrealized/Unrecognized Losses	(8,234)	(8,624)
U.S. State and Municipal securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	0	2,546
Less than 12 Months, Unrealized/Unrecognized Losses	0	(527)
12 months or more, Estimated Fair Value	9,498	6,666
12 months or more, Unrealized/Unrecognized Losses	(2,075)	(1,910)
Total, Estimated Fair Value	9,498	9,212
Total, Unrealized/Unrecognized Losses	(2,075)	(2,437)
U.S. State and Municipal securities | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	0	13,205
Less than 12 Months, Unrealized/Unrecognized Losses	0	(2,609)
12 months or more, Estimated Fair Value	13,571
12 months or more, Unrealized/Unrecognized Losses	(2,122)
Total, Estimated Fair Value	13,571	13,205
Total, Unrealized Losses	(2,122)	(2,609)
Residential MBS | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	0	19,576
Less than 12 Months, Unrealized/Unrecognized Losses	0	(1,654)
12 months or more, Estimated Fair Value	306,686	305,936
12 months or more, Unrealized/Unrecognized Losses	(74,578)	(74,075)
Total, Estimated Fair Value	306,686	325,512
Total, Unrealized/Unrecognized Losses	(74,578)	(75,729)
Residential MBS | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	49,536	162,960
Less than 12 Months, Unrealized/Unrecognized Losses	(2,863)	(19,625)
12 months or more, Estimated Fair Value	319,969	226,661
12 months or more, Unrealized/Unrecognized Losses	(64,714)	(47,402)
Total, Estimated Fair Value	369,505	389,621
Total, Unrealized Losses	(67,577)	(67,027)
Commercial MBS | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	23,378	13,406
Less than 12 Months, Unrealized/Unrecognized Losses	(442)	(198)
12 months or more, Estimated Fair Value	10,997	11,386
12 months or more, Unrealized/Unrecognized Losses	(2,198)	(2,031)
Total, Estimated Fair Value	34,375	24,792
Total, Unrealized/Unrecognized Losses	(2,640)	(2,229)
Commercial MBS | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 Months, Unrealized/Unrecognized Losses	0	0
12 months or more, Estimated Fair Value	6,730	6,835
12 months or more, Unrealized/Unrecognized Losses	(1,370)	(1,276)
Total, Estimated Fair Value	6,730	6,835
Total, Unrealized Losses	(1,370)	(1,276)
Asset-backed Securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 Months, Unrealized/Unrecognized Losses	0	0
12 months or more, Estimated Fair Value	3,371	3,765
12 months or more, Unrealized/Unrecognized Losses	(133)	(188)
Total, Estimated Fair Value	3,371	3,765
Total, Unrealized/Unrecognized Losses	(133)	(188)
US Treasury Securities | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	0	18,683
Less than 12 Months, Unrealized/Unrecognized Losses	0	(1,365)
12 months or more, Estimated Fair Value	27,756	8,946
12 months or more, Unrealized/Unrecognized Losses	(2,118)	(858)
Total, Estimated Fair Value	27,756	27,629
Total, Unrealized Losses	$ (2,118)	$ (2,223)