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
Statement of Comprehensive Income [Abstract]
Net Income	$ 392.9	$ 367.3	$ 751.2	$ 607.7
Other Comprehensive Income (Loss)
Change in Net Unrealized Loss on Securities (net of tax expense (benefit) of $(155.0); $(721.4); $64.6; $(1,496.5))	(557.4)	(2,681.0)	265.8	(5,574.8)
Change in the Effect of Discount Rate Assumptions on the Liability for Future Policy Benefits, Net of Reinsurance (net of tax expense (benefit) of $76.1; $903.5; $(76.8); $1,886.3)	260.1	3,371.4	(313.8)	7,029.5
Change in Net Gain (Loss) on Hedges (net of tax benefit of $10.5; $1.6; $5.8; $4.5)	(41.1)	(5.0)	(23.7)	(15.4)
Change in Foreign Currency Translation Adjustment (net of tax expense of $1.2; $5.2; $1.0; $6.1)	38.3	(61.4)	63.0	(93.4)
Change in Unrecognized Pension and Postretirement Benefit Costs (net of tax expense (benefit) of $1.5; $2.0; $(0.1); $2.9)	(4.8)	(5.0)	0.6	(9.2)
Net Other Comprehensive Income (Loss)	(295.3)	629.0	(9.3)	1,355.1
Comprehensive Income (Loss)	$ 97.6	$ 996.3	$ 741.9	$ 1,962.8