Commitments - Extended Warranty Liability (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Movement in deferred income
Amortization of deferred revenue	$ (3,500)	$ (3,500)
Current portion	12,134		$ 11,165
Noncurrent portion	3,481		$ 3,445
Extended Warranty
Movement in deferred income
Beginning Balance	533	566
Revenue deferred for new extended warranty contracts	36	46
Amortization of deferred revenue	(64)	(69)
Other	(3)	5
Ending Balance	503	548
Current portion	242	260
Noncurrent portion	$ 261	$ 288

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.

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- References

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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130531-203044

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- Definition

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

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-Name Accounting Standards Codification
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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

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-Name Accounting Standards Codification
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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.

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