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Significant Transaction (Universal Studios Japan) (Details) - USD ($) $ in Millions		6 Months Ended
	Apr. 06, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests		$ 0	$ 2,299
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests		$ 0	$ 2,299
Universal Studios Japan [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests	$ 2,300
Universal Studios Japan [Member] | NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests	$ 2,300

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- Definition

The cash outflow associated with the purchase of noncontrolling interest during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

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