Other income (expense) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Income and Expenses [Abstract]
Investment and interest income	$ 59	$ 32		$ 139	$ 86
Foreign exchange gains (losses)	(81)	(29)		(160)	(189)
Royalty Income, Nonoperating	29	27		96	74
Gain on sale of affiliated company	4	36	$ 85	4	121
Net periodic pension and OPEB income (cost), excluding service cost	85	68		257	172
Miscellaneous income (loss)	6	(2)		14	(4)
Other income (expense)	$ 102	$ 132		$ 350	$ 260

This element represents the miscellaneous nonoperating income and loss incurred during the period.

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount of expense (reversal of expense) for net periodic pension and postretirement costs excluding the current service cost component. Includes, but is not limited to, interest cost, actual return on plan assets, amortization of loss (gain), amortization of prior service cost (credit), amortization of transition obligation (asset), loss (gain) from a settlement or curtailment, and certain termination benefits.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

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-Topic 830
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109240200&loc=d3e30690-110894

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- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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- Definition

Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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- References

No definition available.

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- Definition

Amount of income (expense) related to nonoperating activities, classified as other.

+ References

+ Details

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- Definition

Ancillary revenue earned during the period from the consideration paid to the entity for the use of its rights and property by another party. Examples include licensing the use of copyrighted materials and leasing the extraction of natural resources.

+ References

+ Details

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