Commitments - Extended Warranty Liability (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Movement in deferred income
Amortization of deferred revenue	$ (3,800)	$ (4,000)	$ (5,700)	$ (6,000)
Current portion	11,261		11,261		$ 11,165
Noncurrent portion	3,474		3,474		$ 3,445
Extended Warranty
Movement in deferred income
Beginning Balance			533	566
Revenue deferred for new extended warranty contracts			81	111
Amortization of deferred revenue			(128)	(134)
Other			0	(9)
Ending Balance	486	534	486	534
Current portion	225	254	225	254
Noncurrent portion	$ 260	$ 280	$ 260	$ 280

Increase in contract with customer liability for new contracts.

No definition available.

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- Definition

Increase (decrease) in contract with customer liability for other changes not specified in the taxonomy, including foreign currency translation adjustments.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Period Type:	instant

- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable, classified as current.

+ References

+ Details

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- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

+ Details

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- Details

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Namespace Prefix:
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Period Type: