Segment Information (Summary Of Operating Revenues And Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 44,588	$ 45,739	$ 134,372	$ 122,763
Operations and Support Expenses	29,738	30,304	90,482	82,289
EBITDA	14,850	15,435	43,890	40,474
Depreciation and Amortization	6,949	8,166	21,256	20,538
Operating Income (Loss)	7,901	7,269	22,634	19,936
Equity in Net Income (Loss) of Affiliates	3	(64)	36	(71)
Segment Contribution	4,886	6,207	15,330	19,128
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	45,481	46,489	137,032	123,190
Operations and Support Expenses	29,721	30,639	90,207	80,340
EBITDA	15,760	15,850	46,825	42,850
Depreciation and Amortization	5,047	5,009	15,033	14,836
Operating Income (Loss)	10,713	10,841	31,792	28,014
Equity in Net Income (Loss) of Affiliates	28	(31)	162	(34)
Segment Contribution	10,741	10,810	31,954	27,980
Consolidations [Member]
Segment Reporting Information [Line Items]
Revenue	407	531	1,290	1,636
Operations and Support Expenses	703	141	2,129	1,832
EBITDA	(296)	390	(839)	(196)
Depreciation and Amortization	131	829	505	1,034
Operating Income (Loss)	(427)	(439)	(1,344)	(1,230)
Consolidations [Member] | Acquisition-related items [Member]
Segment Reporting Information [Line Items]
Revenue	0	0	(72)	0
Operations and Support Expenses	190	362	579	750
EBITDA	(190)	(362)	(651)	(750)
Depreciation and Amortization	1,771	2,329	5,719	4,669
Operating Income (Loss)	(1,961)	(2,691)	(6,370)	(5,419)
Eliminations and consolidations [Member]
Segment Reporting Information [Line Items]
Revenue	(1,300)	(1,281)	(3,878)	(2,063)
Operations and Support Expenses	(915)	(913)	(2,814)	(1,040)
EBITDA	(385)	(368)	(1,064)	(1,023)
Depreciation and Amortization	0	(1)	(1)	(1)
Operating Income (Loss)	(385)	(367)	(1,063)	(1,022)
Certain Significant Items [Member]
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operations and Support Expenses	39	75	381	407
EBITDA	(39)	(75)	(381)	(407)
Depreciation and Amortization	0	0	0	0
Operating Income (Loss)	(39)	(75)	(381)	(407)
Communications [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	35,401	36,007	105,837	106,498
Operations and Support Expenses	22,767	23,281	67,379	68,273
EBITDA	12,634	12,726	38,458	38,225
Depreciation and Amortization	4,598	4,575	13,740	13,724
Operating Income (Loss)	8,036	8,151	24,718	24,501
Equity in Net Income (Loss) of Affiliates	0	(1)	0	(3)
Segment Contribution	8,036	8,150	24,718	24,498
Communications [Member] | Mobility [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	17,701	17,735	52,356	51,965
Operations and Support Expenses	9,948	10,104	29,511	29,603
EBITDA	7,753	7,631	22,845	22,362
Depreciation and Amortization	2,011	2,057	6,027	6,218
Operating Income (Loss)	5,742	5,574	16,818	16,144
Equity in Net Income (Loss) of Affiliates	0	1	(1)	0
Segment Contribution	5,742	5,575	16,817	16,144
Communications [Member] | Entertainment Group [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	11,197	11,589	33,893	34,498
Operations and Support Expenses	8,797	9,155	25,839	26,623
EBITDA	2,400	2,434	8,054	7,875
Depreciation and Amortization	1,316	1,331	3,978	3,986
Operating Income (Loss)	1,084	1,103	4,076	3,889
Equity in Net Income (Loss) of Affiliates	1	1	1	(1)
Segment Contribution	1,085	1,104	4,077	3,888
Communications [Member] | Business Wireline [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	6,503	6,683	19,588	20,035
Operations and Support Expenses	4,022	4,022	12,029	12,047
EBITDA	2,481	2,661	7,559	7,988
Depreciation and Amortization	1,271	1,187	3,735	3,520
Operating Income (Loss)	1,210	1,474	3,824	4,468
Equity in Net Income (Loss) of Affiliates	(1)	(3)	0	(2)
Segment Contribution	1,209	1,471	3,824	4,466
WarnerMedia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	7,846	8,204	24,575	9,709
Operations and Support Expenses	5,167	5,503	17,449	6,496
EBITDA	2,679	2,701	7,126	3,213
Depreciation and Amortization	150	134	384	166
Operating Income (Loss)	2,529	2,567	6,742	3,047
Equity in Net Income (Loss) of Affiliates	15	(39)	137	(55)
Segment Contribution	2,544	2,528	6,879	2,992
WarnerMedia [Member] | Turner [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	3,007	2,988	9,860	3,767
Operations and Support Expenses	1,460	1,487	5,813	1,933
EBITDA	1,547	1,501	4,047	1,834
Depreciation and Amortization	68	59	167	71
Operating Income (Loss)	1,479	1,442	3,880	1,763
Equity in Net Income (Loss) of Affiliates	10	7	46	39
Segment Contribution	1,489	1,449	3,926	1,802
WarnerMedia [Member] | Home Box Office [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	1,819	1,644	5,045	1,925
Operations and Support Expenses	1,072	991	3,124	1,162
EBITDA	747	653	1,921	763
Depreciation and Amortization	33	25	67	30
Operating Income (Loss)	714	628	1,854	733
Equity in Net Income (Loss) of Affiliates	10	2	40	1
Segment Contribution	724	630	1,894	734
WarnerMedia [Member] | Warner Bros. [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	3,333	3,720	10,240	4,227
Operations and Support Expenses	2,706	3,104	8,543	3,507
EBITDA	627	616	1,697	720
Depreciation and Amortization	39	40	122	54
Operating Income (Loss)	588	576	1,575	666
Equity in Net Income (Loss) of Affiliates	(25)	(23)	(19)	(24)
Segment Contribution	563	553	1,556	642
WarnerMedia [Member] | Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	(313)	(148)	(570)	(210)
Operations and Support Expenses	(71)	(79)	(31)	(106)
EBITDA	(242)	(69)	(539)	(104)
Depreciation and Amortization	10	10	28	11
Operating Income (Loss)	(252)	(79)	(567)	(115)
Equity in Net Income (Loss) of Affiliates	20	(25)	70	(71)
Segment Contribution	(232)	(104)	(497)	(186)
Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	1,730	1,833	5,205	5,809
Operations and Support Expenses	1,625	1,746	4,910	5,353
EBITDA	105	87	295	456
Depreciation and Amortization	284	297	868	942
Operating Income (Loss)	(179)	(210)	(573)	(486)
Equity in Net Income (Loss) of Affiliates	13	9	25	24
Segment Contribution	(166)	(201)	(548)	(462)
Latin America [Member] | Vrio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	1,013	1,102	3,112	3,710
Operations and Support Expenses	851	877	2,598	2,894
EBITDA	162	225	514	816
Depreciation and Amortization	162	168	496	559
Operating Income (Loss)	0	57	18	257
Equity in Net Income (Loss) of Affiliates	13	9	25	24
Segment Contribution	13	66	43	281
Latin America [Member] | Mexico [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	717	731	2,093	2,099
Operations and Support Expenses	774	869	2,312	2,459
EBITDA	(57)	(138)	(219)	(360)
Depreciation and Amortization	122	129	372	383
Operating Income (Loss)	(179)	(267)	(591)	(743)
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Segment Contribution	(179)	(267)	(591)	(743)
Xandr [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	504	445	1,415	1,174
Operations and Support Expenses	162	109	469	218
EBITDA	342	336	946	956
Depreciation and Amortization	15	3	41	4
Operating Income (Loss)	327	333	905	952
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Segment Contribution	327	333	905	952
Corporate [Member]
Segment Reporting Information [Line Items]
Revenue	$ 407	$ 531	$ 1,218	$ 1,636