Schedule of Components of Unrealized Gain (Loss) on Securities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Change in Components of Net Unrealized Gain on Securities
Change in Net Unrealized Gain on Securities	$ (2,893.8)	$ (1,646.0)
Fixed Maturity Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	5,949.3	7,597.6
Change in Net Unrealized Gain on Securities	(3,668.9)	(2,080.2)
End of Period Balance	2,280.4	5,517.4
Deferred Acquisition Costs
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(70.4)	(85.1)
Change in Net Unrealized Gain on Securities	36.8	18.5
End of Period Balance	(33.6)	(66.6)
Reserve for Future Policy and Contract Benefits
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(4,659.5)	(6,225.6)
Change in Net Unrealized Gain on Securities	2,555.1	1,636.7
End of Period Balance	(2,104.4)	(4,588.9)
Reinsurance Recoverable
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	132.1	200.2
Change in Net Unrealized Gain on Securities	(57.3)	(66.9)
End of Period Balance	74.8	133.3
Income Tax
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	(389.3)	(419.4)
Change in Net Unrealized Gain on Securities	238.2	102.4
End of Period Balance	(151.1)	(317.0)
Net Unrealized Gain on Securities
Change in Components of Net Unrealized Gain on Securities
Beginning of Period Balance	962.2	1,067.7
Change in Net Unrealized Gain on Securities	(896.1)	(389.5)
End of Period Balance	$ 66.1	$ 678.2