Fair Value of Financial Instruments - Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
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
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	782.8	590.7
Short-term debt	0.0	0.0
Long-term debt	277.4	331.1
Level 3
Financial Assets
Other investments	152.4	172.1
Deposit asset on reinsurance	2,935.1	3,030.6
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	5,004.9	4,963.3
Investment contract and life policy reserves, account values on life contracts	115.4	108.4
Other policyholder funds	56.5	56.1
Short-term debt	249.0	135.0
Long-term debt	0.0	0.0
Carrying Value
Financial Assets
Other investments	148.8	168.3
Deposit asset on reinsurance	2,481.5	2,420.9
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	4,941.3	4,847.6
Investment contract and life policy reserves, account values on life contracts	105.4	98.7
Other policyholder funds	839.3	646.8
Short-term debt	249.0	135.0
Long-term debt	253.6	302.3
Fair Value
Financial Assets
Other investments	152.4	172.1
Deposit asset on reinsurance	2,935.1	3,030.6
Financial Liabilities
Investment contract and policy reserves, fixed annuity contracts	5,004.9	4,963.3
Investment contract and life policy reserves, account values on life contracts	115.4	108.4
Other policyholder funds	839.3	646.8
Short-term debt	249.0	135.0
Long-term debt	$ 277.4	$ 331.1

Deposit Asset On Reinsurance Fair Value Disclosure

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- Definition

Financial assets.

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

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- Definition

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

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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

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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.

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- Definition

Amount of investments classified as other.

+ References

Reference 1: 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 http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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.

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