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LOANS AND CREDIT QUALITY - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 13,852,209	$ 14,176,936
Accrued interest receivable	$ 51,700	$ 53,100
Commercial And Residential Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percent of total loans	76.00%	76.00%
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 5,291,597	$ 5,355,252
Commercial real estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 5,291,597	$ 5,355,252
Percent of total loans	38.00%	38.00%
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 4,017,120	$ 3,970,803
Percent of total loans	29.00%	28.00%
Federal Home Loan Bank Advances | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 10,300,000
Federal Reserve Bank Advances | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan receivables	$ 1,300,000

X

- Definition

Percentage, before allowance for credit loss, of financing receivable to total financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
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Amount, after allowance for credit loss, of accrued interest on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
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-Section 50
-Paragraph 3A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3A

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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