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Preparation Of Interim Financial Statements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Change in Accounting Estimate [Line Items]
Diluted Earnings Per Share Attributable to Common Stock	$ 0.17	$ 0.51	$ 0.81	$ 1.06
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Retained earnings	$ 56,045		$ 56,045			$ 57,936
Contract asset	2,546		2,546			2,472
Deferred income taxes	58,387		58,387			59,502
Goodwill, Impairment Loss	2,319	$ 0	2,442	$ 0
Noncontrolling interest	17,557		$ 17,557			$ 17,713
Communications [Member] \| Orbital Slots [Member] \| Intangible Assets, Amortization Period [Member]
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate, Description			Also during the first quarter of 2020, in conjunction with the nationwide launch of AT&T TV and our customers’ continued shift from linear to streaming video services, we reassessed the estimated economic lives and renewal assumptions for our orbital slot licenses. As a result, we have changed the estimated lives of these licenses from indefinite to finite-lived, effective January 1, 2020, and began amortizing our orbital slot licenses using the sum-of-months-digits method over their average remaining economic life of 15 years.
Estimated economic useful life			15 years
Amortization expense	$ 379		$ 765
Diluted Earnings Per Share Attributable to Common Stock	$ 0.04		$ 0.08
Latin America [Member] \| Vrio [Member] \| Venezuela
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Disposal Date			Jun. 30, 2020
Goodwill, Impairment Loss			$ 2,212
Noncontrolling interest	$ (105)		$ (105)
Latin America [Member] \| Trade Names [Member] \| Intangible Assets, Amortization Period [Member]
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate, Description			During the first quarter of 2020, we reassessed and changed the estimated economic lives of certain trade names in our Latin America business from indefinite to finite-lived and began amortizing them using the straight-line method over their average remaining economic life of 15 years.
Estimated economic useful life			15 years
ASU 2016-13 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
ASU Adoption Date [CCYY-MM-DD format]					Jan. 01, 2020
ASU Early Adoption [true/false]					false
Transition Option Elected [Prospective/Retrospective/Modified Prospective/Modified Retrospective]					Modified Retrospective
Prior Period Not Restated [true/false]			true
Significant effect on the financial statements [Yes/No]			No
Retained earnings					$ (293)
Allowance for doubtful accounts					395
Contract asset					(10)
Deferred income taxes					(105)
Noncontrolling interest					$ (7)