INVESTMENT SECURITIES (Schedule of Securities with Unrealized Losses) (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($) item	Dec. 31, 2021 USD ($) 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	133,203	477,140
Less than 12 Months, Unrealized/Unrecognized Losses	(26,968)	(11,075)
12 months or more, Estimated Fair Value	290,062	53,509
12 months or more, Unrealized/Unrecognized Losses	(62,684)	(1,751)
Total, Estimated Fair Value	423,265	530,649
Total, Unrealized/Unrecognized Losses	(89,652)	(12,826)
Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	448,868	319,632
Less than 12 Months, Unrealized/Unrecognized Losses	(72,508)	(2,401)
Total, Estimated Fair Value	448,868	319,632
Total, Unrealized Losses	(72,508)	(2,401)
Residential MBS | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	128,285	423,686
Less than 12 Months, Unrealized/Unrecognized Losses	(26,149)	(9,727)
12 months or more, Estimated Fair Value	208,956	12,931
12 months or more, Unrealized/Unrecognized Losses	(49,364)	(738)
Total, Estimated Fair Value	337,241	436,617
Total, Unrealized/Unrecognized Losses	(75,513)	(10,465)
Residential MBS | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	402,078	301,896
Less than 12 Months, Unrealized/Unrecognized Losses	(65,465)	(2,259)
Total, Estimated Fair Value	402,078	301,896
Total, Unrealized Losses	(65,465)	(2,259)
Commercial MBS | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	2,497	11,202
Less than 12 Months, Unrealized/Unrecognized Losses	(154)	(296)
12 months or more, Estimated Fair Value	11,712	3,511
12 months or more, Unrealized/Unrecognized Losses	(1,947)	(83)
Total, Estimated Fair Value	14,209	14,713
Total, Unrealized/Unrecognized Losses	(2,101)	(379)
Commercial MBS | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	6,800	8,039
Less than 12 Months, Unrealized/Unrecognized Losses	(1,316)	(99)
Total, Estimated Fair Value	6,800	8,039
Total, Unrealized Losses	(1,316)	(99)
Asset-backed Securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value		4,613
Less than 12 Months, Unrealized/Unrecognized Losses		(22)
12 months or more, Estimated Fair Value	3,992
12 months or more, Unrealized/Unrecognized Losses	(179)
Total, Estimated Fair Value	3,992	4,613
Total, Unrealized/Unrecognized Losses	(179)	(22)
U.S. Government agency securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value		29,267
Less than 12 Months, Unrealized/Unrecognized Losses		(730)
12 months or more, Estimated Fair Value	58,832	37,067
12 months or more, Unrealized/Unrecognized Losses	(9,163)	(930)
Total, Estimated Fair Value	58,832	66,334
Total, Unrealized/Unrecognized Losses	(9,163)	(1,660)
U.S. State and Municipal securities | Available-for-sale Securities.
Available-for-sale Securities
Less than 12 Months, Estimated Fair Value	2,421	8,372
Less than 12 Months, Unrealized/Unrecognized Losses	(665)	(300)
12 months or more, Estimated Fair Value	6,570
12 months or more, Unrealized/Unrecognized Losses	(2,031)
Total, Estimated Fair Value	8,991	8,372
Total, Unrealized/Unrecognized Losses	(2,696)	(300)
U.S. State and Municipal securities | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	12,567
Less than 12 Months, Unrealized/Unrecognized Losses	(3,308)
Total, Estimated Fair Value	12,567
Total, Unrealized Losses	(3,308)
US Treasury Securities | Held-to-maturity Securities
Held-to-maturity Securities
Less than 12 Months, Estimated Fair Value	27,423	9,697
Less than 12 Months, Unrealized/Unrecognized Losses	(2,419)	(43)
Total, Estimated Fair Value	27,423	9,697
Total, Unrealized Losses	$ (2,419)	$ (43)