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Allowance for Credit Losses (Non-accrual Basis By Loan Class) (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | $ 41,997 | $ 51,648
Commercial, financial and agricultural | Domestic | Commercial. |  |
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | 31,269 | 30,747
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial |  |
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | 298 | 94
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily |  |
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | 100 | 117
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development |  |
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | 10,087 | 20,483
Real estate - mortgage | Domestic | Residential: first lien |  |
Loan loss allowances, financing receivable past due |  |
Non-accrual loans, total | $ 243 | $ 207

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