Reportable Segments (Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 20,843	$ 24,238
Assets of discontinued operations	13	4,596
Long-Lived Assets	14,194	17,883
United States [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	13,699	17,476
International [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	495	407
Operating Segments [Member] \| Entertainment [Member]
Segment Reporting Information [Line Items]
Assets	12,626	11,262
Operating Segments [Member] \| Cable Networks [Member]
Segment Reporting Information [Line Items]
Assets	2,878	2,618
Operating Segments [Member] \| Publishing [Member]
Segment Reporting Information [Line Items]
Assets	906	880
Operating Segments [Member] \| Local Media [Member]
Segment Reporting Information [Line Items]
Assets	4,042	4,065
Corporate/Eliminations [Member]
Segment Reporting Information [Line Items]
Assets	$ 378	$ 817

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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Amount classified as assets attributable to disposal group held for sale or disposed of.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (e)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e1107-107759

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Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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