Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Loss	$ (97.1)	$ (72.2)	$ (177.2)	$ (158.5)
Other Comprehensive Income (Loss) Before Income Taxes
Change in Net Unrecognized Postretirement Benefit Costs	(0.6)	0.0	(1.1)	(0.1)
(Loss) Gain on Cash Flow Hedges	(0.1)	(0.2)	(0.1)	5.9
Change in Discount Rate on Future Life Policyholder Benefits	50.6	527.7	(59.2)	1,090.0
Other Comprehensive Income (Loss) Before Income Taxes	(33.4)	(52.7)	43.5	(136.4)
Other Comprehensive Income Tax (Expense) Benefit	7.3	11.1	(9.4)	28.6
Other Comprehensive Income (Loss), Net of Taxes	(26.1)	(41.6)	34.1	(107.8)
Total Comprehensive Loss	(123.2)	(113.8)	(143.1)	(266.3)
No Credit Losses Recognized in Condensed Consolidated Statements of Loss
Other Comprehensive Income (Loss) Before Income Taxes
Changes in Net Unrealized Holding Gains (Losses) on Investment Securities with:	(83.2)	(587.1)	104.0	(1,231.7)
Credit Losses Recognized in Condensed Consolidated Statements of Loss
Other Comprehensive Income (Loss) Before Income Taxes
Changes in Net Unrealized Holding Gains (Losses) on Investment Securities with:	$ (0.1)	$ 6.9	$ (0.1)	$ (0.5)