Schedule of Components of Unrealized Gain (Loss) on Securities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Change in Components of Net Unrealized Gain on Securities
Change in Net Unrealized Gain on Securities	$ (2,681.1)	$ 858.8	$ (5,574.9)	$ (787.2)
Fixed Maturity Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	2,280.4	5,517.4	5,949.3	7,597.6
Change in Net Unrealized Gain on Securities	(3,402.4)	1,085.7	(7,071.3)	(994.5)
End of Period Balance	(1,122.0)	6,603.1	(1,122.0)	6,603.1
Deferred Acquisition Costs
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(33.6)	(66.6)	(70.4)	(85.1)
Change in Net Unrealized Gain on Securities	25.5	(13.2)	62.3	5.3
End of Period Balance	(8.1)	(79.8)	(8.1)	(79.8)
Reserve for Future Policy and Contract Benefits
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(2,104.4)	(4,588.9)	(4,659.5)	(6,225.6)
Change in Net Unrealized Gain on Securities	2,000.2	(797.7)	4,555.3	839.0
End of Period Balance	(104.2)	(5,386.6)	(104.2)	(5,386.6)
Reinsurance Recoverable
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	74.8	133.3	132.1	200.2
Change in Net Unrealized Gain on Securities	(55.1)	19.5	(112.4)	(47.4)
End of Period Balance	19.7	152.8	19.7	152.8
Income Tax
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(151.1)	(317.0)	(389.3)	(419.4)
Change in Net Unrealized Gain on Securities	300.8	(61.1)	539.0	41.3
End of Period Balance	149.7	(378.1)	149.7	(378.1)
Net Unrealized Gain (Loss) on Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	66.1	678.2	962.2	1,067.7
Change in Net Unrealized Gain on Securities	(1,131.0)	233.2	(2,027.1)	(156.3)
End of Period Balance	$ (1,064.9)	$ 911.4	$ (1,064.9)	$ 911.4