Collateralized Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Federal Home Loan Bank, Advances	$ 804.7	$ 643.8
Federal Home Loan Bank, Collateral Posted to FHLB	1,819.0	1,862.6
Policyholders' Account Balance	6,494.8	5,636.4
February 2026 FABL
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Funding Agreement-Backed Note, Collateral Pledged	683.7	0.0
Policyholders' Account Balance	500.0	0.0
April 2026 Senior LOC Facility
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Amount Outstanding on Line of Credit	0.0	0.0
Debt Instrument, Collateral Amount	83.1	0.0
Fixed Maturity Securities
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Federal Home Loan Bank, Collateral Posted to FHLB	716.9	752.4
Fixed Maturity Securities \| February 2026 FABL
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Funding Agreement-Backed Note, Collateral Pledged	680.4	0.0
Fixed Maturity Securities \| April 2026 Senior LOC Facility
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Debt Instrument, Collateral Amount	83.1	0.0
Commercial Mortgage Loans
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Federal Home Loan Bank, Collateral Posted to FHLB	1,102.1	1,110.2
Commercial Mortgage Loans \| February 2026 FABL
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Funding Agreement-Backed Note, Collateral Pledged	0.0	0.0
Commercial Mortgage Loans \| April 2026 Senior LOC Facility
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Debt Instrument, Collateral Amount	0.0	0.0
Cash and Cash Equivalents
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Federal Home Loan Bank, Collateral Posted to FHLB	0.0	0.0
Cash and Cash Equivalents \| February 2026 FABL
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Funding Agreement-Backed Note, Collateral Pledged	3.3	0.0
Cash and Cash Equivalents \| April 2026 Senior LOC Facility
Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances
Debt Instrument, Collateral Amount	$ 0.0	$ 0.0

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Funding Agreement-Backed Note, Collateral Pledged

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Amount of assets pledged to secure a debt instrument.

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Amount of advance from Federal Home Loan Bank (FHLBank).

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

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount due to policyholder. Includes, but is not limited to, unpaid policy dividend, retrospective refund, and undistributed earnings on participating business. Excludes future policy benefit and claim expense.

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