Segments (Revenue and Plant Property Equipment by Countries) (Details 6) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 USD ($) Customer	Dec. 31, 2013 USD ($) Customer
Segment Information
Revenue	$ 81,741	$ 92,793	$ 98,367
Net Plant, Property and Equipment	$ 10,727	$ 10,771
Revenue \| Major Client
Segment Information
Concentration Risk, Percentage	10.00%
Number of clients represented 10% or more of the company's total revenue \| Customer	0	0	0
Revenue \| Geographic Information
Segment Information
Revenue	$ 81,741	$ 92,793	$ 98,367
Concentration Risk, Percentage	10.00%
Plant and Other Property - Net \| Geographic Information
Segment Information
Concentration Risk, Percentage	10.00%
Plant and Other Property - Net
Segment Information
Net Plant, Property and Equipment	$ 10,176	10,078	12,979
Geographic Information \| Plant and Other Property - Net
Segment Information
Net Plant, Property and Equipment	10,176	10,078	12,979
UNITED STATES \| Revenue \| Geographic Information
Segment Information
Revenue	30,514	32,021	33,427
UNITED STATES \| Geographic Information \| Plant and Other Property - Net
Segment Information
Net Plant, Property and Equipment	4,644	4,388	6,723
Other countries \| Revenue \| Geographic Information
Segment Information
Revenue	51,227	60,772	64,941
Other countries \| Geographic Information \| Plant and Other Property - Net
Segment Information
Net Plant, Property and Equipment	$ 5,532	$ 5,690	$ 6,257

The number of customers that represent 10 percent or more of the company's total revenue.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
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- Definition

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13)
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-Publisher SEC
-Name Regulation S-X (SX)
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-Section 02
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-Name Regulation S-X (SX)
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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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