Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income, Net of Tax
Balance, Beginning of Period	$ 3.4	$ 631.9	$ 166.4	$ 255.0
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	25.1	(74.4)	(132.2)	322.5
Reclassification from Accumulated Other Comprehensive Income or Loss	(6.5)	(8.9)	(12.2)	(28.9)
Net Other Comprehensive Income (Loss)	18.6	(83.3)	(144.4)	293.6
Balance, End of Period	22.0	548.6	22.0	548.6
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income, Net of Tax
Balance, Beginning of Period	112.1	501.2	290.3	135.7
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	47.0	(35.5)	(137.6)	328.3
Reclassification from Accumulated Other Comprehensive Income or Loss	(0.5)	(3.7)	5.9	(2.0)
Net Other Comprehensive Income (Loss)	46.5	(39.2)	(131.7)	326.3
Balance, End of Period	158.6	462.0	158.6	462.0
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income, Net of Tax
Balance, Beginning of Period	391.7	369.5	391.0	396.3
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	21.3	19.9	37.9	16.1
Reclassification from Accumulated Other Comprehensive Income or Loss	(7.9)	(5.9)	(23.8)	(28.9)
Net Other Comprehensive Income (Loss)	13.4	14.0	14.1	(12.8)
Balance, End of Period	405.1	383.5	405.1	383.5
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax
Balance, Beginning of Period	(102.5)	(9.3)	(113.4)	(47.1)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(44.1)	(60.2)	(33.2)	(22.4)
Reclassification from Accumulated Other Comprehensive Income or Loss	0.0	0.0	0.0	0.0
Net Other Comprehensive Income (Loss)	(44.1)	(60.2)	(33.2)	(22.4)
Balance, End of Period	(146.6)	(69.5)	(146.6)	(69.5)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income, Net of Tax
Balance, Beginning of Period	(397.9)	(229.5)	(401.5)	(229.9)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	0.9	1.4	0.7	0.5
Reclassification from Accumulated Other Comprehensive Income or Loss	1.9	0.7	5.7	2.0
Net Other Comprehensive Income (Loss)	2.8	2.1	6.4	2.5
Balance, End of Period	$ (395.1)	$ (227.4)	$ (395.1)	$ (227.4)