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Acquisitions, Dispositions And Other Adjustments (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2020	May 31, 2020	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Acquisition and Dispositions [Line Items]
Acquisitions, net of cash acquired				$ 1,174	$ 320
Acquisition of business - Goodwill	$ 143,651		$ 143,651	143,651		$ 146,241
FCC Licenses [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - acquisition date	Jun. 30, 2020
Payments to Acquire Intangible Assets				2,379
37 GHz Licenses [Member]
Acquisition and Dispositions [Line Items]
Payments to Acquire Intangible Assets			949	1,186
FiberTower Corporation [Member] \| FCC Licenses [Member]
Acquisition and Dispositions [Line Items]
Value of consideration received in a noncash transaction				1,200
FiberTower Corporation [Member] \| 39 GHz Licenses [Member]
Acquisition and Dispositions [Line Items]
Indefinite-lived Intangible Assets - value	$ 300		$ 300	300
Gain (Loss) on disposition of intangible asset				$ 900
WarnerMedia [Member] \| HBO LAG [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - acquisition date		May 31, 2020
Acquisitions, net of cash acquired		$ 141
Acquisition of business, remeasurement gain		68
Acquisition of business - Goodwill		343
Acquisition of intangible assets, trade names		640
WarnerMedia [Member] \| HBO LAG [Member] \| Distribution Networks - Net
Acquisition and Dispositions [Line Items]
Acquisition of other intangible assets		$ 271