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LOANS AND CREDIT QUALITY - Narrative (Details) - USD ($) $ in Thousands | Mar. 31, 2026 | Dec. 31, 2025
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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 |

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- 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 + Details
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