Retirement Benefits (Schedule of Benefit Obligations and Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Document Period End Date	Dec. 31, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	$ 9,976.4	$ 10,423.8
Defined Benefit Plan, Service Cost	240.9	287.1	253.1
Defined Benefit Plan, Interest Cost	472.6	437.2	455.1
Defined Benefit Plan, Actuarial Net (Gains) Losses	1,996.3	(792.2)
Defined Benefit Plan, Benefits Paid	(421.2)	(402.3)
Defined Benefit Plan, Plan Amendments	(2.4)	(0.1)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Benefit Obligation	(250.2)	22.9
Defined Benefit Plan, Benefit Obligation, Ending Balance	12,012.4	9,976.4	10,423.8
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	9,481.7	8,286.6
Defined Benefit Plan, Actual Return on Plan Assets	813.6	1,144.6
Defined Benefit Plan, Contributions by Employer	127.2	428.9
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(165.6)	23.9
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	9,835.7	9,481.7	8,286.6
Defined Benefit Plan, Funded Status of Plan	(2,176.7)	(494.7)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	5,114.9	3,546.3
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	43.5	50.7
Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total	2,981.7	3,102.3
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	1,757.2	2,337.7
Defined Benefit Plan, Service Cost	33.0	49.9	63.3
Defined Benefit Plan, Interest Cost	85.6	98.1	114.9
Defined Benefit Plan, Actuarial Net (Gains) Losses	293.5	(642.5)
Defined Benefit Plan, Benefits Paid	(76.1)	(79.6)
Defined Benefit Plan, Plan Amendments	(533.6)	(4.1)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Benefit Obligation	(6.1)	(2.3)
Defined Benefit Plan, Benefit Obligation, Ending Balance	1,553.5	1,757.2	2,337.7
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	1,879.6	1,518.0
Defined Benefit Plan, Actual Return on Plan Assets	157.4	365.7
Defined Benefit Plan, Contributions by Employer	(42.2)	75.5
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	0	0
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	1,918.7	1,879.6	1,518.0
Defined Benefit Plan, Funded Status of Plan	365.2	122.4
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	439.5	178.1
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	(666.7)	(171.5)
Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total	138.0	129.0
Fair Value, Inputs, Level 2 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	5,076.2	4,860.1
Fair Value, Inputs, Level 2 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	1,579.6	1,533.9
Fair Value, Inputs, Level 3 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	2,822.2	2,603.2	2,274.9
Fair Value, Inputs, Level 3 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	216.5	211.1	182.2
Fair Value, Inputs, Level 1 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	1,937.3	2,018.4
Fair Value, Inputs, Level 1 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	122.6	134.6
Equity Securities [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	411.4	400.3
Equity Securities [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	39.2	39.4
Equity Securities [Member] \| Fair Value, Inputs, Level 2 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	227.6	211.1
Equity Securities [Member] \| Fair Value, Inputs, Level 2 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	22.0	21.1
Equity Securities [Member] \| Fair Value, Inputs, Level 3 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0
Equity Securities [Member] \| Fair Value, Inputs, Level 3 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0
Equity Securities [Member] \| Fair Value, Inputs, Level 1 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	183.8	189.2
Equity Securities [Member] \| Fair Value, Inputs, Level 1 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	17.2	18.3
Equity Securities - International [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	2,337.8	2,483.8
Equity Securities - International [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	158.9	167.2
Equity Securities - International [Member] \| Fair Value, Inputs, Level 2 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	1,338.1	1,438.0
Equity Securities - International [Member] \| Fair Value, Inputs, Level 2 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	100.1	105.6
Equity Securities - International [Member] \| Fair Value, Inputs, Level 3 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0
Equity Securities - International [Member] \| Fair Value, Inputs, Level 3 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0
Equity Securities - International [Member] \| Fair Value, Inputs, Level 1 [Member] \| Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	999.7	1,045.8
Equity Securities - International [Member] \| Fair Value, Inputs, Level 1 [Member] \| Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	$ 58.8	$ 61.6

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