Investments (Investments Pledged as Collateral) (Details) $ in Millions	Sep. 30, 2023 USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	$ 22.2
Securities owned and pledged as collateral, fair value	119.6
Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	64.2
Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	33.2
U.S. Government and Government Agencies [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	18.7
Securities owned and pledged as collateral, fair value	18.7
U.S. Government and Government Agencies [Member] \| Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	0.0
U.S. Government and Government Agencies [Member] \| Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	0.0
Obligations of States and Political Subdivisions [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	3.5
Securities owned and pledged as collateral, fair value	3.5
Obligations of States and Political Subdivisions [Member] \| Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	0.0
Obligations of States and Political Subdivisions [Member] \| Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	0.0
Residential Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	0.0
Securities owned and pledged as collateral, fair value	86.4
Residential Mortgage Backed Securities [Member] \| Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	61.7
Residential Mortgage Backed Securities [Member] \| Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	24.7
Commercial Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	0.0
Securities owned and pledged as collateral, fair value	11.0
Commercial Mortgage Backed Securities [Member] \| Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	2.5
Commercial Mortgage Backed Securities [Member] \| Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral with FHLB	$ 8.5

Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions.

No definition available.

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- Definition

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 825
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479383/944-825-50-1A

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480876/942-470-45-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480848/942-470-50-3

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481444/860-30-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(11))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1

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