Revenue Recognition (Revenue Categories) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 44,827	$ 38,038
Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	14,167	13,766
Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	5,256	4,921
Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,087	3,671
Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	12,160	9,343
Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,651	0
Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,772	392
Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,591	1,553
Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	4,143	4,392
Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	167	333
Corporate and Other [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Corporate and Other [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	167	333
Corporate and Other [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	45,916	38,007
Operating Segments [Member] | Communications [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	35,393	35,533
Operating Segments [Member] | Communications [Member] | Mobility [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	17,567	17,355
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	13,725	13,362
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	67	41
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,775	3,952
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	11,328	11,431
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,070	1,878
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	683	806
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	7,724	7,891
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	350	334
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	501	519
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	3
Operating Segments [Member] | Communications [Member] | Business Wireline [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	6,498	6,747
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,186	3,043
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	2,404	2,865
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	749	669
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	159	170
Operating Segments [Member] | WarnerMedia [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	8,379	112
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,443	112
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,965	98
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	135	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,261	14
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	82	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,510	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,334	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	173	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,518	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	21	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3,332	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	10	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	155	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(92)
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	49	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(152)	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	8	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	3	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,718	2,025
Operating Segments [Member] | Latin America [Member] | Vrio [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,067	1,354
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	1,067	1,354
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	651	671
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	442	404
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	209	267
Operating Segments [Member] | Xandr [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	426	337
Operating Segments [Member] | Xandr [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	426	337
Operating Segments [Member] | Xandr [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Operating Segments [Member] | Xandr [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Eliminations and consolidations [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(1,256)	(302)
Eliminations and consolidations [Member] | Eliminations and other [Member]
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(1,256)	(302)
Eliminations and consolidations [Member] | Eliminations and other [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Eliminations and consolidations [Member] | Eliminations and other [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Eliminations and consolidations [Member] | Eliminations and other [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Eliminations and consolidations [Member] | Eliminations and other [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total Operating Revenues	0	0
Eliminations and consolidations [Member] | Eliminations and other [Member] | Content
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(837)	0
Eliminations and consolidations [Member] | Eliminations and other [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(350)	(334)
Eliminations and consolidations [Member] | Eliminations and other [Member] | Other
Disaggregation of Revenue [Line Items]
Total Operating Revenues	(69)	32
Eliminations and consolidations [Member] | Eliminations and other [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total Operating Revenues	$ 0	$ 0