Schedule of Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income
Balance, Beginning of Period	$ 454.4	$ 485.7	$ 255.0	$ 628.0
Other Comprehensive Income Before Reclassifications, Net of Tax	193.8	(270.4)	396.9	(413.1)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	(16.3)	1.4	(20.0)	1.8
Net Other Comprehensive Income (Loss)	177.5	(269.0)	376.9	(411.3)
Balance, End of Period	631.9	216.7	631.9	216.7
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income
Balance, Beginning of Period	325.3	792.4	135.7	873.5
Other Comprehensive Income Before Reclassifications, Net of Tax	176.6	(493.1)	363.8	(566.4)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	(0.7)	(3.7)	1.7	(11.5)
Net Other Comprehensive Income (Loss)	175.9	(496.8)	365.5	(577.9)
Balance, End of Period	501.2	295.6	501.2	295.6
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income
Balance, Beginning of Period	398.0	399.6	396.3	401.6
Other Comprehensive Income Before Reclassifications, Net of Tax	(12.3)	8.7	(3.8)	7.5
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	(16.2)	(2.8)	(23.0)	(3.6)
Net Other Comprehensive Income (Loss)	(28.5)	5.9	(26.8)	3.9
Balance, End of Period	369.5	405.5	369.5	405.5
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(39.5)	(142.5)	(47.1)	(72.6)
Other Comprehensive Income Before Reclassifications, Net of Tax	30.2	0.9	37.8	(69.0)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	0	0	0	0
Net Other Comprehensive Income (Loss)	30.2	0.9	37.8	(69.0)
Balance, End of Period	(9.3)	(141.6)	(9.3)	(141.6)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(229.4)	(563.8)	(229.9)	(574.5)
Other Comprehensive Income Before Reclassifications, Net of Tax	(0.7)	213.1	(0.9)	214.8
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	0.6	7.9	1.3	16.9
Net Other Comprehensive Income (Loss)	(0.1)	221.0	0.4	231.7
Balance, End of Period	$ (229.5)	$ (342.8)	$ (229.5)	$ (342.8)