Retirement Benefits (Schedule of Components in Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accrued retirement benefit		$ 3,068.5	$ 1,887.4
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Current Assets		160.8	58.5
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities		(57.5)	(54.7)
Accrued retirement benefit		2,108.2	1,135.8
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax		4,914.8	3,852.7
Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total		2,909.9	2,720.7
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	285.3	(200.4)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	3.3	(8.6)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Current Assets		0	0
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities		(9.3)	(9.2)
Accrued retirement benefit		960.3	751.6
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax		1,152.3	974.2
Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total		182.7	213.4
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	95.7	(88.7)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	$ 35.1	$ 42.9