Schedule of Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income
Balance, Beginning of Period	$ 485.7		$ 628.0
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(270.4)		(413.1)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss, Net of Tax	1.4		1.8
Total Other Comprehensive Income (Loss)	(269.0)	145.1	(411.3)	138.7
Balance, End of Period	216.7		216.7
Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income
Balance, Beginning of Period	792.4		873.5
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	(493.1)		(566.4)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss, Net of Tax	(3.7)		(11.5)
Total Other Comprehensive Income (Loss)	(496.8)		(577.9)
Balance, End of Period	295.6		295.6
Net Gain on Cash Flow Hedges
Accumulated Other Comprehensive Income
Balance, Beginning of Period	399.6		401.6
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	8.7		7.5
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss, Net of Tax	(2.8)		(3.6)
Total Other Comprehensive Income (Loss)	5.9		3.9
Balance, End of Period	405.5		405.5
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(142.5)		(72.6)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	0.9		(69.0)
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss, Net of Tax	0		0
Total Other Comprehensive Income (Loss)	0.9		(69.0)
Balance, End of Period	(141.6)		(141.6)
Unrecognized Pension and Postretirement Benefit Costs
Accumulated Other Comprehensive Income
Balance, Beginning of Period	(563.8)		(574.5)
Other Comprehensive Income (Loss) Before Reclassifications, Net of Tax	213.1		214.8
Amounts Reclassified from Accumulated Other Comprehensive Income or Loss, Net of Tax	7.9		16.9
Total Other Comprehensive Income (Loss)	221.0		231.7
Balance, End of Period	$ (342.8)		$ (342.8)