Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Service Cost	$ 66.7	$ 57.7	$ 193.8	$ 174.7
Defined Benefit Plan, Interest Cost	113.0	111.8	338.7	335.8
Defined Benefit Plan, Expected Return on Plan Assets	(171.2)	(171.9)	(512.6)	(515.2)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0.8	2.2	2.5	6.9
Defined Benefit Plan, Actuarial Gain (Loss)	71.4	50.4	213.3	149.2
Defined Benefit Plan, Net Periodic Benefit Cost, Total	80.7	50.2	235.7	151.4
Pension and Other Postretirement Benefit Contributions			60
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	10		10
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Service Cost	16.1	14.4	48.4	43.1
Defined Benefit Plan, Interest Cost	28.6	29.5	85.6	88.6
Defined Benefit Plan, Expected Return on Plan Assets	(31.8)	(31.9)	(95.4)	(95.7)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(8.8)	(10.7)	(26.3)	(32.2)
Defined Benefit Plan, Actuarial Gain (Loss)	24.6	22.2	72.9	66.5
Defined Benefit Plan, Net Periodic Benefit Cost, Total	28.7	23.5	85.2	70.3
Pension and Other Postretirement Benefit Contributions			$ 340