Retirement Benefits (Schedule of Expected Benefit Payments, Contributions and Expense) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year, Description		$ 40.0
Defined Benefit Plan, Accumulated Benefit Obligation		10,750.0	$ 10,880.0
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Benefit Obligation		10,054.1	10,537.2
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets		8,069.7	8,149.2
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax	[1]	(80.7)	(34.0)	$ (31.9)
Change in defined benefit pension and retiree health benefit plans		(572.9)	1,327.6	(2,592.2)
Defined Contribution Plan, Cost Recognized		162.4	153.3	147.7
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year, Description		5.0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Expected Future Benefit Payments in Year One		(458.4)
Defined Benefit Plan, Expected Future Benefit Payments in Year Two		(465.2)
Defined Benefit Plan, Expected Future Benefit Payments in Year Three		(480.3)
Defined Benefit Plan, Expected Future Benefit Payments in Year Four		(498.8)
Defined Benefit Plan, Expected Future Benefit Payments in Year Five		(518.5)
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter		(2,987.5)
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation		2,028.1	2,179.8
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets		844.9	700.9
Defined Benefit Plan, Service Cost		315.7	240.9	287.1
Defined Benefit Plan, Interest Cost		476.8	472.6	437.2
Defined Benefit Plan, Expected Return on Plan Assets		(782.3)	(756.6)	(701.9)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)		10.4	3.6	3.7
Defined Benefit Plan, Amortization of Gains (Losses)		383.2	282.3	414.7
Defined Benefit Plan, Amortization of Net Gains (Losses)		285.9
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)		11.9
Defined Benefit Plan, Net Periodic Benefit Cost, Total		403.8	242.8	440.8
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax		(120.4)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax		0.4
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax		(10.4)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax		(383.2)
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year		297.8
Foreign currency translation gains (losses)		58.8
Change in defined benefit pension and retiree health benefit plans		573.2
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Expected Future Benefit Payments in Year One		(70.7)
Defined Benefit Plan, Expected Future Benefit Payments in Year Two		(75.3)
Defined Benefit Plan, Expected Future Benefit Payments in Year Three		(78.3)
Defined Benefit Plan, Expected Future Benefit Payments in Year Four		(81.1)
Defined Benefit Plan, Expected Future Benefit Payments in Year Five		(84.0)
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter		(464.2)
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation		245.8	244.2
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets		0.0	0.0
Defined Benefit Plan, Service Cost		45.1	33.0	49.9
Defined Benefit Plan, Interest Cost		62.6	85.6	98.1
Defined Benefit Plan, Expected Return on Plan Assets		(150.0)	(146.4)	(130.7)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)		(91.1)	(37.6)	(35.6)
Defined Benefit Plan, Amortization of Gains (Losses)		38.0	20.7	100.5
Defined Benefit Plan, Amortization of Net Gains (Losses)		19.2
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)		(85.8)
Defined Benefit Plan, Net Periodic Benefit Cost, Total		(95.4)	$ (44.7)	$ 82.2
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax		(48.6)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax		0.0
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost, before Tax		91.1
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax		(38.0)
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year		(66.6)
Foreign currency translation gains (losses)		4.2
Change in defined benefit pension and retiree health benefit plans		$ (0.3)

[1] (1) These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 14).