Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e848-128460

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e845-128460

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

Segment Information (Summary Of Operating Revenues And Expenses) (Narrative) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018
Segment Reporting Information [Line Items]
Number of Reportable Segments	4
Amortization of production costs	$ 2,497	$ 0
Time Warner Inc. [Member]
Segment Reporting Information [Line Items]
Business Acquisition, Effective Date of Acquisition			Jun. 14, 2018
Corporate and Other [Member] \| Time Warner Inc. [Member] \| Pre-Acquisition Released Programming Costs Member [Member]
Segment Reporting Information [Line Items]
Amortization of production costs	$ 150