Schedule of Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income
Balance, Beginning of Period	$ 255.0	$ 628.0
After Tax Other Comprehensive Income Before Reclassifications	203.1	(142.7)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	(3.7)	0.4
Net Other Comprehensive Income (Loss)	199.4	(142.3)
Balance, End of Period	454.4	485.7
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income
Balance, Beginning of Period	135.7	873.5
After Tax Other Comprehensive Income Before Reclassifications	187.2	(73.3)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	2.4	(7.8)
Net Other Comprehensive Income (Loss)	189.6	(81.1)
Balance, End of Period	325.3	792.4
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income
Balance, Beginning of Period	396.3	401.6
After Tax Other Comprehensive Income Before Reclassifications	8.5	(1.2)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	(6.8)	(0.8)
Net Other Comprehensive Income (Loss)	1.7	(2.0)
Balance, End of Period	398.0	399.6
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(47.1)	(72.6)
After Tax Other Comprehensive Income Before Reclassifications	7.6	(69.9)
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	0	0
Net Other Comprehensive Income (Loss)	7.6	(69.9)
Balance, End of Period	(39.5)	(142.5)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(229.9)	(574.5)
After Tax Other Comprehensive Income Before Reclassifications	(0.2)	1.7
Reclassifications from Accumulated Other Comprehensive Income, Net of Tax	0.7	9.0
Net Other Comprehensive Income (Loss)	0.5	10.7
Balance, End of Period	$ (229.4)	$ (563.8)