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Fair value disclosure only table (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
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Assets, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | $ 1,569,107 | $ 1,705,120 |
Loans and Leases Receivable, Net Amount |  | 14,135,848 | 13,776,256 |
Securities held to maturity, fair value |  | 1,417,608 | 1,524,710 |
Federal Home Loan Bank Stock |  | 43,557 | 5,218 |
Bank Owned Life Insurance |  | 297,387 | 293,323 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Federal Home Loan Bank borrowings |  | 1,105,541 | 637 |
Subordinated Debt |  | 49,980 | 49,885 |
Deposits [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Financial Liabilities Book Value |  | 12,684,068 | 14,683,266 |
Accrued Liabilities, Fair Value Disclosure | [1] | 12,684,068 | 14,683,266 |
Bank Time Deposits [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Financial Liabilities Book Value |  | 2,181,479 | 1,195,741 |
Accrued Liabilities, Fair Value Disclosure | [2] | 2,166,573 | 1,164,892 |
Federal Home Loan Bank Advances [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Federal Home Loan Bank borrowings |  | 1,105,541 | 637 |
Federal Home Loan Bank Borrowings, Fair Value Disclosure | [2] | 1,103,845 | 563 |
Junior Subordinated Debt [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Junior subordinated debentures (less unamortized debt issuance costs of $30 and $33) |  | 62,858 | 62,855 |
Accrued Liabilities, Fair Value Disclosure | [3] | 58,911 | 60,002 |
Subordinated Debt [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Subordinated Debt |  | 49,980 | 49,885 |
Accrued Liabilities, Fair Value Disclosure | [2] | 49,613 | 45,891 |
Significant Other Observable Inputs (Level 2) [Member] | Deposits [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Accrued Liabilities, Fair Value Disclosure |  | 12,684,068 | 14,683,266 |
Significant Other Observable Inputs (Level 2) [Member] | Bank Time Deposits [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Accrued Liabilities, Fair Value Disclosure |  | 2,166,573 | 1,164,892 |
Significant Other Observable Inputs (Level 2) [Member] | Federal Home Loan Bank Advances [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 1,103,845 | 563 |
Significant Other Observable Inputs (Level 2) [Member] | Junior Subordinated Debt [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Accrued Liabilities, Fair Value Disclosure |  | 58,911 | 60,002 |
Significant Unobservable Inputs (Level 3) [Member] | Subordinated Debt [Member] |  |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Accrued Liabilities, Fair Value Disclosure |  | 49,613 | 45,891 |
US Government Agencies Debt Securities [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 28,408 | 29,036 | [4]
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 29,521 | 31,258 |
US Government Agencies Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 28,408 | 29,036 |
US Treasury Securities [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value | [4] | 91,535 | 88,879 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 100,712 | 100,634 |
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 91,535 | 88,879 |
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value | [4] | 763,728 | 815,952 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 829,431 | 898,927 |
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 763,728 | 815,952 |
Collateralized Mortgage Obligations [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value | [4] | 407,911 | 458,417 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 477,517 | 535,971 |
Collateralized Mortgage Obligations [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 407,911 | 458,417 |
Single Issuer Trust Preferred Securities Issued By Banks [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value | [4] | 1,373 | 1,508 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 1,500 | 1,500 |
Single Issuer Trust Preferred Securities Issued By Banks [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 1,373 | 1,508 |
Small Business Administration Pooled Securities [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value | [4] | 124,653 | 130,918 |
Liabilities, Fair Value Disclosure [Abstract] |  |  |  |
Debt Securities, Held-to-maturity |  | 130,426 | 136,830 |
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 0 | 0 |
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 124,653 | 130,918 |
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Securities held to maturity, fair value |  | 0 | 0 |
Loans Net Of Allowance For Loan Loses [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Loans and Leases Receivable, Net Amount |  | 14,106,967 | 13,760,164 |
Loans, net of allowance for loan losses | [5] | 13,079,368 | 13,260,873 |
Loans Net Of Allowance For Loan Loses [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Loans, net of allowance for loan losses |  | 13,079,368 | 13,260,873 |
Investment in Federal Home Loan Bank Stock [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Federal Home Loan Bank Stock |  | 43,557 | 5,218 |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure | [6] | 43,557 | 5,218 |
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure |  | 0 | 0 |
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure |  | 43,557 | 5,218 |
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure |  | 0 | 0 |
Cash Surrender Value [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Bank Owned Life Insurance |  | 297,387 | 293,323 |
Cash Surrender Value, Fair Value Disclosure | [7] | 297,387 | 293,323 |
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Cash Surrender Value, Fair Value Disclosure |  | 0 | 0 |
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Cash Surrender Value, Fair Value Disclosure |  | 297,387 | 293,323 |
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |  |
Cash Surrender Value, Fair Value Disclosure |  | $ 0 | $ 0 |
[1] | Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date.
[2] | Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities.
[3] | Fair value was determined based upon market prices of securities with similar terms and maturities.
[4] | The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis.
[5] | Fair value of loans is measured using the exit price valuation method, determined primarily by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows, while incorporating liquidity and credit assumptions. Additionally, this amount excludes individually assessed collateral dependent loans, which are deemed to be marked to fair value on a nonrecurring basis.
[6] | Federal Home Loan Bank stock has no quoted market value and is carried at cost, therefore the carrying amount approximates fair value.
[7] | Cash surrender value of life insurance is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore, carrying amount approximates fair value.

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- Definition The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
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