SECURITIES - Held-to-maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Securities held-to-maturity:
Amortized Cost	$ 605,642	$ 585,798
Gross Unrecognized Gains	139
Gross Unrecognized Losses	(73,209)	(80,039)
Fair Value	532,572	505,759
Agency Notes
Securities held-to-maturity:
Amortized Cost	89,258	89,157
Gross Unrecognized Losses	(11,619)	(14,095)
Fair Value	77,639	75,062
Corporate Securities
Securities held-to-maturity:
Amortized Cost	9,000	9,000
Gross Unrecognized Losses	(2,063)	(553)
Fair Value	6,937	8,447
Pass-through mortgage-backed securities ("MBS") issued by government sponsored entities ("GSEs")
Securities held-to-maturity:
Amortized Cost	290,698	278,281
Gross Unrecognized Gains	123
Gross Unrecognized Losses	(37,137)	(40,960)
Fair Value	253,684	237,321
Agency collateralized mortgage obligations ("CMOs")
Securities held-to-maturity:
Amortized Cost	216,686	209,360
Gross Unrecognized Gains	16
Gross Unrecognized Losses	(22,390)	(24,431)
Fair Value	$ 194,312	$ 184,929

Amount excluding accrued interest, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 320
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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