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BORROWINGS (Narrative) (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2023 | Dec. 31, 2022
Subordinated Borrowing [Line Items] |  |
Remaining available balance for the federal funds lines | $ 737,000 | $ 1,000,000
Maximum collateral dependent line of credit with the FHLB | 6,200,000 | 6,000,000
Remaining credit availability on collateral dependent line of credit with the FHLB | 5,700,000 | 4,900,000
Trust Preferred Capital Securities | 150,500 | 150,500
Fair value discount | 14,426 | 15,296
Subordinated Debt | 250,000 | 250,000
Remaining borrowing capacity | 25,000 | 25,000
Federal Reserve Bank Term Funding Program |  |
Subordinated Borrowing [Line Items] |  |
Additional funding available | 531,000 |
Acquired Trust Preferred Capital Notes |  |
Subordinated Borrowing [Line Items] |  |
Fair value discount | 11,900 | 12,500
2031 Subordinate Debt |  |
Subordinated Borrowing [Line Items] |  |
Subordinated Debt | $ 250,000 | $ 250,000
Stated percentage on debt instrument | 2.875% | 2.875%
Three-month CME SOFR rate plus | 0.00% | 0.00%
Maturity date | Dec. 15, 2031 | Dec. 15, 2031
Previous bank acquisitions | Trust Preferred Capital Notes |  |
Subordinated Borrowing [Line Items] |  |
Trust Preferred Capital Securities | $ 58,500 |
Previous bank acquisitions | Acquired Trust Preferred Capital Notes |  |
Subordinated Borrowing [Line Items] |  |
Trust Preferred Capital Securities | $ 92,000 |

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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
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