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Long-Term Debt and Other Borrowed Funds (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021 | May 31, 2020
--- | --- | --- | ---
Debt Instrument |  |  |
Stated interest rate |  |  | 5.25%
Long-term debt | $ 98.9 | $ 98.7 |
Long-term debt and capital lease obligations | 120.8 | 112.4 |
Fiscal Year Maturities of Long-term Debt |  |  |
2018 | 0.1 |  |
2019 | 0.1 |  |
2020 | 0.1 |  |
2021 | 0.1 |  |
2022 | 0.2 |  |
Thereafter | 120.2 |  |
Long-term debt and capital lease obligations | 120.8 | 112.4 |
Advances from FHLB | 2,327.0 | 0.0 |
Other borrowings | 2,327.0 | 0.0 |
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net | 1.1 |  |
Other Borrowings | 0.0 |  |
Federal Home Loan Bank Advances | $ 0.0 |  |
FIB |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Ownership percentage in subsidiary | 99.90% |  |
Parent |  |  |
Debt Instrument |  |  |
Long-term debt | $ 98.9 | $ 98.7 |
4.60% variable rate overnight borrowings |  |  |
Debt Instrument |  |  |
Stated interest rate | 4.60% |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Advances from FHLB | $ 827.0 |  |
4.48% fixed rate borrowings in tenors up to one-month |  |  |
Debt Instrument |  |  |
Stated interest rate | 4.48% |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Advances from FHLB | $ 1,500.0 |  |
Capital lease obligations | Capital Lease Obligation, 8.00% | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate |  | 8.00% |
Finance Lease, Liability | 1.0 | $ 1.0 |
Notes payable | Subsidiaries |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Long Term Debt, Acquired or Assumed | 20.9 | 12.7 |
Notes payable | Note Payable, 1.30%, maturing March 31, 2038 [Member] | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | 2.0 | 2.0 |
Notes payable | Note Payable, 1.30%, Maturing June 1, 2034 [Member] | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | $ 0.6 | 0.6 |
Notes payable | Note Payable, One Percent | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 1.00% |  |
Notes payable | Note Payable, 2.28% | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | $ 0.0 | 5.0 |
Notes payable | Note Payable, 1.00% | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | $ 5.1 | 5.1 |
Notes payable | Note Payable, One Point Three Percent | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 1.30% |  |
Notes payable | Note Payable, One Point Three Zero Percent | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 1.30% |  |
Notes payable | Note Payable, Three Point Two Five Percent | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 3.25% |  |
Notes payable | Note Payable, 1.12%, Maturing December 31, 2045 | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | $ 6.8 | 0.0 |
Notes payable | Note Payable, 1.35%, Maturing December 31, 2046 | Subsidiaries |  |  |
Debt Instrument |  |  |
Long-term debt | 6.4 | $ 0.0 |
Federal Home Loan Bank | Notes Payable to FHLB | Subsidiaries |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
FHLB, advances, maximum amount available | 4,768.0 |  |
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds | 2,441.0 |  |
Secured Debt |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Line of credit facility, maximum borrowing capacity | 763.3 |  |
Federal Funds Purchased |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Line of credit facility, maximum borrowing capacity | 235.0 |  |
Unsecured Debt [Member] |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Line of credit facility, maximum borrowing capacity | $ 100.0 |  |
Subordinated term loan | Subordinated Notes Due May 2030 |  |  |
Fiscal Year Maturities of Long-term Debt |  |  |
Debt Instrument, Face Amount |  |  | $ 100.0
Minimum | Note Payable, 1.00% | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 1.00% |  |
Maximum [Member] | Note Payable, Three Point Two Five Percent | Subsidiaries |  |  |
Debt Instrument |  |  |
Stated interest rate | 3.25% |  |

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