Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	$ 16.1	$ 166.4
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	182.0	92.7
Reclassification from Accumulated Other Comprehensive Income or Loss	2.6	1.3
Net Other Comprehensive Income (Loss)	184.6	94.0
Balance at End of Period	200.7	260.4
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	204.3	290.3
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	223.8	118.0
Reclassification from Accumulated Other Comprehensive Income or Loss	10.3	6.0
Net Other Comprehensive Income (Loss)	234.1	124.0
Balance at End of Period	438.4	414.3
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	378.0	391.0
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(15.9)	27.6
Reclassification from Accumulated Other Comprehensive Income or Loss	(10.3)	(6.7)
Net Other Comprehensive Income (Loss)	(26.2)	20.9
Balance at End of Period	351.8	411.9
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	(173.6)	(113.4)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(26.4)	(54.0)
Reclassification from Accumulated Other Comprehensive Income or Loss	0.0	0.0
Net Other Comprehensive Income (Loss)	(26.4)	(54.0)
Balance at End of Period	(200.0)	(167.4)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income, Net of Tax
Balance at Beginning of Period	(392.6)	(401.5)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	0.5	1.1
Reclassification from Accumulated Other Comprehensive Income or Loss	2.6	2.0
Net Other Comprehensive Income (Loss)	3.1	3.1
Balance at End of Period	$ (389.5)	$ (398.4)