Investments - Sales of Fixed Maturities and Equity Securities (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019
Fixed maturity securities
Proceeds received		$ 578.2	$ 472.9	$ 805.9
Gross gains realized		10.5	20.5	150.9
Gross losses realized		(7.7)	(6.1)	(7.8)
Equity securities
Proceeds received		4.7	12.7	29.9
Gross gains realized		1.5	2.2	9.2
Gross losses realized		(0.1)	$ (1.9)	(0.8)
Investment gain realized on transfer	$ 135.3
Reinsurance block of in-force fixed and variable annuity business		$ 3,200.0		$ 2,900.0	$ 2,900.0

Investment Gain (Loss) On Reinsurance

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- Definition

Proceeds From Sale And Maturity Of Marketable Securities (Excluding FHLB Repayments)

+ References

No definition available.

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- Definition

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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- Definition

Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

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-Publisher FASB
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Amount of realized loss from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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- Definition

Amount of cash inflow from sale, maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

+ References

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