Schedule of Components of Unrealized Gain (Loss) on Securities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Change in Components of Net Unrealized Gain on Securities
Change in Net Unrealized Gain on Securities	$ (1,925.8)	$ (260.8)	$ (7,500.7)	$ (1,048.0)
Fixed Maturity Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(1,122.0)	6,603.1	5,949.3	7,597.6
Change in Net Unrealized Gain on Securities	(2,446.6)	(329.8)	(9,517.9)	(1,324.3)
End of Period Balance	(3,568.6)	6,273.3	(3,568.6)	6,273.3
Deferred Acquisition Costs
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(8.1)	(79.8)	(70.4)	(85.1)
Change in Net Unrealized Gain on Securities	21.6	6.8	83.9	12.1
End of Period Balance	13.5	(73.0)	13.5	(73.0)
Reserve for Future Policy and Contract Benefits
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(104.2)	(5,386.6)	(4,659.5)	(6,225.6)
Change in Net Unrealized Gain on Securities	868.5	242.7	5,423.8	1,081.7
End of Period Balance	764.3	(5,143.9)	764.3	(5,143.9)
Reinsurance Recoverable
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	19.7	152.8	132.1	200.2
Change in Net Unrealized Gain on Securities	(44.4)	(14.6)	(156.8)	(62.0)
End of Period Balance	(24.7)	138.2	(24.7)	138.2
Income Tax
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	149.7	(378.1)	(389.3)	(419.4)
Change in Net Unrealized Gain on Securities	336.5	19.5	875.5	60.8
End of Period Balance	486.2	(358.6)	486.2	(358.6)
Net Unrealized Gain (Loss) on Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(1,064.9)	911.4	962.2	1,067.7
Change in Net Unrealized Gain on Securities	(1,264.4)	(75.4)	(3,291.5)	(231.7)
End of Period Balance	$ (2,329.3)	$ 836.0	$ (2,329.3)	$ 836.0