Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	$ 354.1	$ 374.2
Other Comprehensive Income (Loss) Before Reclassifications	(936.5)	(447.2)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	(2.3)	(48.1)
Total Other Comprehensive Loss	(934.2)	(399.1)
Balance at End of Period	(580.1)	(24.9)
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	962.2	1,067.7
Other Comprehensive Income (Loss) Before Reclassifications	(906.1)	(447.2)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	(10.0)	(57.7)
Total Other Comprehensive Loss	(896.1)	(389.5)
Balance at End of Period	66.1	678.2
Net Gain on Hedges
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	61.8	97.8
Other Comprehensive Income (Loss) Before Reclassifications	0.4	(6.8)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	10.8	13.9
Total Other Comprehensive Loss	(10.4)	(20.7)
Balance at End of Period	51.4	77.1
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	(273.9)	(261.3)
Other Comprehensive Income (Loss) Before Reclassifications	(31.9)	7.3
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	0.0	0.0
Total Other Comprehensive Loss	(31.9)	7.3
Balance at End of Period	(305.8)	(254.0)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	(396.0)	(530.0)
Other Comprehensive Income (Loss) Before Reclassifications	1.1	(0.5)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	(3.1)	(4.3)
Total Other Comprehensive Loss	4.2	3.8
Balance at End of Period	$ (391.8)	$ (526.2)