Long Term Debt, Acquired or Assumed

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount of Federal Home Loan Bank (FHLBank) advances to member financial institutions.

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Present value of lessee's discounted obligation for lease payments from finance lease.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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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%