Retirement Benefits (Summary of changes in the fair value of the plans’ Level 3 assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	$ 1,507	$ 1,430
Purchases	279	247
Sales	(253)	(282)
Unrealized Gain/(Loss)	(86)	(144)
Realized Gain/(Loss)	153	176
Exchange Rate Impact	(75)	3
Transfers in/(out) and Other	4	83
Fair Value, Asset Value, Ending	1,529	1,507
Private equity/partnerships [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	799	824
Purchases	158	146
Sales	(185)	(174)
Unrealized Gain/(Loss)	(173)	(155)
Realized Gain/(Loss)	137	150
Exchange Rate Impact	(12)	(1)
Transfers in/(out) and Other	3	9
Fair Value, Asset Value, Ending	727	799
Real Estate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	312	357
Purchases	97	21
Sales	(50)	(95)
Unrealized Gain/(Loss)	19	6
Realized Gain/(Loss)	16	26
Exchange Rate Impact	(19)	(3)
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	375	312
Other Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	238	239
Purchases	21	18
Sales	(16)	(13)
Unrealized Gain/(Loss)	18	10
Realized Gain/(Loss)	0	0
Exchange Rate Impact	(28)	6
Transfers in/(out) and Other	6	(22)
Fair Value, Asset Value, Ending	239	238
Common/Collective trusts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	151	0
Purchases	0	61
Sales	(1)	0
Unrealized Gain/(Loss)	50	(4)
Realized Gain/(Loss)	0	0
Exchange Rate Impact	(16)	(5)
Transfers in/(out) and Other	0	99
Fair Value, Asset Value, Ending	184	151
Corporate stocks [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	1	9
Purchases	0	0
Sales	0	0
Unrealized Gain/(Loss)	0	0
Realized Gain/(Loss)	0	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	0	(8)
Fair Value, Asset Value, Ending	1	1
Corporate Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	4	1
Purchases	3	1
Sales	(1)	0
Unrealized Gain/(Loss)	0	0
Realized Gain/(Loss)	0	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	(3)	2
Fair Value, Asset Value, Ending	3	4
Government Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	2	0
Purchases	0	0
Sales	0	0
Unrealized Gain/(Loss)	0	(1)
Realized Gain/(Loss)	0	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	(2)	3
Fair Value, Asset Value, Ending	$ 0	$ 2

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Translation Adjustment

No definition available.

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- Definition

Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

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- Definition

Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1a)

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

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- Definition

Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

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- Definition

Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

+ References

No definition available.

+ Details

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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