INVESTMENT SECURITIES - Held to maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 31, 2022
INVESTMENT SECURITIES
Amortized Cost	$ 243,843	$ 253,100
Gross Unrealized Losses	(33,629)	(17,071)
Estimated Fair Value	210,214	236,029
Municipal securities
INVESTMENT SECURITIES
Amortized Cost	10,344	10,368
Gross Unrealized Losses	(2,859)	(1,422)
Estimated Fair Value	7,485	8,946
Agency securities
INVESTMENT SECURITIES
Amortized Cost	53,941	45,277
Gross Unrealized Losses	(5,091)	(2,450)
Estimated Fair Value	48,850	42,827
Real estate mortgage investment conduits
INVESTMENT SECURITIES
Amortized Cost	35,186	39,394
Gross Unrealized Losses	(4,769)	(2,457)
Estimated Fair Value	30,417	36,937
Residential mortgage-backed securities
INVESTMENT SECURITIES
Amortized Cost	123,773	137,343
Gross Unrealized Losses	(17,542)	(8,883)
Estimated Fair Value	106,231	128,460
Other mortgage-backed securities
INVESTMENT SECURITIES
Amortized Cost	20,599	20,718
Gross Unrealized Losses	(3,368)	(1,859)
Estimated Fair Value	$ 17,231	$ 18,859

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
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.9-03(6))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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