Fair Value of Financial Instruments - Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Level 1
Financial Assets
Other investments	$ 0.0	$ 0.0
Deposit asset on reinsurance	0.0	0.0
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	0.0	0.0
Investment contract and life policy reserves, account values on life contracts	0.0	0.0
Other policyholder funds	0.0	0.0
Reverse repurchase agreements	0.0	0.0
Short-term debt	0.0	0.0
Long-term debt	0.0	0.0
Level 2
Financial Assets
Other investments	0.0	0.0
Deposit asset on reinsurance	0.0	0.0
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	0.0	0.0
Investment contract and life policy reserves, account values on life contracts	0.0	0.0
Other policyholder funds	810.7	782.8
Reverse repurchase agreements	73.9	0.0
Short-term debt	0.0	0.0
Long-term debt	240.5	277.4
Level 3
Financial Assets
Other investments	170.9	152.4
Deposit asset on reinsurance	2,207.2	2,935.1
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	4,901.3	5,004.9
Investment contract and life policy reserves, account values on life contracts	107.7	115.4
Other policyholder funds	52.3	56.5
Reverse repurchase agreements	0.0	0.0
Short-term debt	249.0	249.0
Long-term debt	0.0	0.0
Carrying Value
Financial Assets
Other investments	167.4	148.8
Deposit asset on reinsurance	2,516.6	2,481.5
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	4,988.5	4,941.3
Investment contract and life policy reserves, account values on life contracts	111.9	105.4
Other policyholder funds	863.0	839.3
Reverse repurchase agreements	70.2	0.0
Short-term debt	249.0	249.0
Long-term debt	249.0	253.6
Fair Value
Financial Assets
Other investments	170.9	152.4
Deposit asset on reinsurance	2,207.2	2,935.1
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	4,901.3	5,004.9
Investment contract and life policy reserves, account values on life contracts	107.7	115.4
Other policyholder funds	863.0	839.3
Reverse repurchase agreements	73.9	0.0
Short-term debt	249.0	249.0
Long-term debt	$ 240.5	$ 277.4

Deposit Asset On Reinsurance Fair Value Disclosure

No definition available.

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- Definition

Financial assets.

+ References

No definition available.

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- Definition

Investment Contract And Life Policy Reserves, Account Values On Life Contracts, Fair Value

+ References

No definition available.

+ Details

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- Definition

Investment Contract And Policy Reserves, Fixed Annuity Contracts, Fair Value

+ References

No definition available.

+ Details

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- Definition

Fair Value of the liability as of the balance sheet date to the policyholders for funds held that are returnable under the terms of insurance contracts that were not separately reported.

+ References

No definition available.

+ Details

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- References

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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- Definition

Amount of investments classified as other.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f,g))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

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- Definition

The carrying value of securities purchased to be resold in reverse repurchase transactions as of the balance sheet date.

+ References

No definition available.

+ Details

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

+ References

No definition available.

+ Details

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