Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	$ 200.7	$ 260.4	$ 16.1	$ 166.4
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	143.9	(250.0)	325.9	(157.3)
Reclassification from Accumulated Other Comprehensive Income or Loss	(4.8)	(7.0)	(2.2)	(5.7)
Net Other Comprehensive Income (Loss)	139.1	(257.0)	323.7	(163.0)
Balance at End of Period	339.8	3.4	339.8	3.4
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	438.4	414.3	204.3	290.3
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	222.0	(302.6)	445.8	(184.6)
Reclassification from Accumulated Other Comprehensive Income or Loss	0.7	0.4	11.0	6.4
Net Other Comprehensive Income (Loss)	222.7	(302.2)	456.8	(178.2)
Balance at End of Period	661.1	112.1	661.1	112.1
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	351.8	411.9	378.0	391.0
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(0.2)	(11.0)	(16.1)	16.6
Reclassification from Accumulated Other Comprehensive Income or Loss	(8.0)	(9.2)	(18.3)	(15.9)
Net Other Comprehensive Income (Loss)	(8.2)	(20.2)	(34.4)	0.7
Balance at End of Period	343.6	391.7	343.6	391.7
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	(200.0)	(167.4)	(173.6)	(113.4)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(79.4)	64.9	(105.8)	10.9
Reclassification from Accumulated Other Comprehensive Income or Loss	0.0	0.0	0.0	0.0
Net Other Comprehensive Income (Loss)	(79.4)	64.9	(105.8)	10.9
Balance at End of Period	(279.4)	(102.5)	(279.4)	(102.5)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	(389.5)	(398.4)	(392.6)	(401.5)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	1.5	(1.3)	2.0	(0.2)
Reclassification from Accumulated Other Comprehensive Income or Loss	2.5	1.8	5.1	3.8
Net Other Comprehensive Income (Loss)	4.0	0.5	7.1	3.6
Balance at End of Period	$ (385.5)	$ (397.9)	$ (385.5)	$ (397.9)