Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	$ (217.1)	$ (502.3)	$ 37.3	$ (814.2)
Other Comprehensive Income (Loss) Before Reclassifications	551.5	262.8	265.5	580.0
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	7.2	3.0	(24.4)	8.3
Total Other Comprehensive Income	544.3	259.8	289.9	571.7
Balance at End of Period	327.2	(242.5)	327.2	(242.5)
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	395.3	(0.1)	615.9	(312.4)
Other Comprehensive Income (Loss) Before Reclassifications	563.6	280.6	300.4	586.0
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	(4.2)	(6.4)	(46.8)	(13.3)
Total Other Comprehensive Income	567.8	287.0	347.2	599.3
Balance at End of Period	963.1	286.9	963.1	286.9
Net Gain on Hedges
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	210.6	230.1	187.8	250.6
Other Comprehensive Income (Loss) Before Reclassifications	(9.3)	0.9	28.4	(3.8)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	15.1	13.0	30.0	28.8
Total Other Comprehensive Income	(24.4)	(12.1)	(1.6)	(32.6)
Balance at End of Period	186.2	218.0	186.2	218.0
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	(345.2)	(287.9)	(281.6)	(305.2)
Other Comprehensive Income (Loss) Before Reclassifications	(3.0)	(19.7)	(66.6)	(2.4)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	0.0	0.0	0.0	0.0
Total Other Comprehensive Income	(3.0)	(19.7)	(66.6)	(2.4)
Balance at End of Period	(348.2)	(307.6)	(348.2)	(307.6)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Year	(477.8)	(444.4)	(484.8)	(447.2)
Other Comprehensive Income (Loss) Before Reclassifications	0.2	1.0	3.3	0.2
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss	(3.7)	(3.6)	(7.6)	(7.2)
Total Other Comprehensive Income	3.9	4.6	10.9	7.4
Balance at End of Period	$ (473.9)	$ (439.8)	$ (473.9)	$ (439.8)