Policyholder Contract Liabilities - Supplemental Financial Information (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Policyholder Contract Liabilities	$ 503.7	$ 309.8
Federal Home Loan Bank of Chicago \| United Insurance Company of America
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Fair Value of Collateral Pledged	484.3	287.8
FHLB of Chicago Common Stock Owned at Cost	11.8	4.9
Federal Home Loan Bank of Chicago \| United Insurance Company of America \| FHLB Funding Agreements
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Policyholder Contract Liabilities	$ 444.1	$ 243.4

Carrying value as of the balance sheet date of the sum of the obligations to contract holders to provide to them an agreed upon rate of return pursuant to the terms of the underlying contract. These contracts represent lending by the contract holders to the entity in return for a guaranteed (primarily fixed) interest rate until maturity, unless called earlier if the contracts provide that option to the contract holders (usually institutions). There is little or no insurance risk for the entity.

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 210.7-03.14)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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+ References

No definition available.

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- Definition

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809

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Fair value of the securities pledged as collateral against securities loaned.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226013-175313

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