Retirement Benefits (Components of the Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 213	$ 252	$ 240
Interest cost	641	581	596
Expected return on plan assets	(990)	(911)	(905)
Amortization of prior service credit	(16)	(22)	(19)
Recognized actuarial loss (credit)	243	315	270
Net periodic benefit (credit) cost	91	215	182
Curtailment gain	(65)	0	0
Total (credit) cost	26	215	182
U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	91	104	93
Interest cost	253	229	230
Expected return on plan assets	(346)	(324)	(322)
Amortization of prior service credit	(7)	(16)	(16)
Recognized actuarial loss (credit)	112	207	152
Net periodic benefit (credit) cost	103	200	137
Non- U.S Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	122	148	147
Interest cost	388	352	366
Expected return on plan assets	(644)	(587)	(583)
Amortization of prior service credit	(9)	(6)	(3)
Recognized actuarial loss (credit)	131	108	118
Net periodic benefit (credit) cost	(12)	15	45
Settlement loss	0	0	1
Curtailment gain	(65)	0	(1)
Total (credit) cost	(77)	15	45
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	5	5
Interest cost	11	11	13
Expected return on plan assets	0	0	0
Amortization of prior service credit	0	0	(14)
Recognized actuarial loss (credit)	(1)	2	0
Net periodic benefit (credit) cost	14	18	4
Curtailment gain	0	0	0
Total (credit) cost	14	18	4
U.S. Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	3
Interest cost	7	7	8
Expected return on plan assets	0	0	0
Amortization of prior service credit	0	0	(13)
Recognized actuarial loss (credit)	(2)	0	(1)
Net periodic benefit (credit) cost	7	10	(3)
Foreign Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	2
Interest cost	4	4	5
Expected return on plan assets	0	0	0
Amortization of prior service credit	0	0	(1)
Recognized actuarial loss (credit)	1	2	1
Net periodic benefit (credit) cost	7	8	7
Settlement loss	0	0	0
Curtailment gain	0	0	0
Total (credit) cost	$ 7	$ 8	$ 7

Defined Benefit Plan, Net Periodic Benefit Cost, Excluding Settlements, Curtailments, and Special Termination Benefits

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- Definition

The amount of gains or losses recognized in net periodic benefit cost.

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

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An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Expected Return on Plan Assets

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- Definition

The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

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- Definition

The amount of net gain (loss) recognized in net periodic benefit cost as a result of an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Glossary Plan Curtailment

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- Definition

Amount of net gain (loss) recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits.

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- Definition

The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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