Goodwill and Other Intangible Assets - Summary of Changes in Carrying Amount of Goodwill (Detail) $ in Millions	9 Months Ended
Sep. 30, 2018 USD ($)
Goodwill [Line Items]
Balance beginning	$ 8,495
Acquisitions, divestitures and other adjustments	25
Effect of foreign currency translation	(66)
Balance ending	8,454
Buy
Goodwill [Line Items]
Balance beginning	2,844
Acquisitions, divestitures and other adjustments	10
Effect of foreign currency translation	(58)
Balance ending	2,796
Watch
Goodwill [Line Items]
Balance beginning	5,651
Acquisitions, divestitures and other adjustments	15
Effect of foreign currency translation	(8)
Balance ending	$ 5,658

Acquisitions, divestitures and other adjustments.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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