Segment Information (Summary Of Operating Revenues And Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ 42,340	$ 44,588	$ 126,069	$ 134,372
Operations and Support Expenses	29,178	29,738	87,382	90,482
EBITDA	13,162	14,850	38,687	43,890
Depreciation and Amortization	7,030	6,949	21,537	21,256
Operating Income	6,132	7,901	17,150	22,634
Equity in Net Income (Loss) of Affiliates	5	3	(11)	36
Income Before Income Taxes	3,934	4,886	12,697	15,330
Operating Segments
Segment Reporting Information [Line Items]
Revenues	43,197	45,481	128,522	137,032
Operations and Support Expenses	28,933	29,721	84,302	90,207
EBITDA	14,264	15,760	44,220	46,825
Depreciation and Amortization	5,048	5,047	15,175	15,033
Operating Income	9,216	10,713	29,045	31,792
Equity in Net Income (Loss) of Affiliates	25	28	56	162
Income Before Income Taxes	9,241	10,741	29,101	31,954
Corporate
Segment Reporting Information [Line Items]
Revenues	431	407	1,256	1,290
Operations and Support Expenses	1,012	703	2,819	2,129
EBITDA	(581)	(296)	(1,563)	(839)
Depreciation and Amortization	61	131	241	505
Operating Income	(642)	(427)	(1,804)	(1,344)
Reconciling Items
Segment Reporting Information [Line Items]
Equity in Net Income (Loss) of Affiliates	(25)	(28)	(56)	(162)
Acquisition-related items
Segment Reporting Information [Line Items]
Revenues	0	0	0	(72)
Operations and Support Expenses	38	190	431	579
EBITDA	(38)	(190)	(431)	(651)
Depreciation and Amortization	1,921	1,771	6,122	5,719
Operating Income	(1,959)	(1,961)	(6,553)	(6,370)
Certain significant items
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operations and Support Expenses	113	39	2,539	381
EBITDA	(113)	(39)	(2,539)	(381)
Depreciation and Amortization	0	0	0	0
Operating Income	(113)	(39)	(2,539)	(381)
Eliminations and consolidations
Segment Reporting Information [Line Items]
Revenues	(1,288)	(1,300)	(3,709)	(3,878)
Operations and Support Expenses	(918)	(915)	(2,709)	(2,814)
EBITDA	(370)	(385)	(1,000)	(1,064)
Depreciation and Amortization	0	0	(1)	(1)
Operating Income	(370)	(385)	(999)	(1,063)
Communications | Operating Segments
Segment Reporting Information [Line Items]
Revenues	34,287	35,401	102,128	105,837
Operations and Support Expenses	22,012	22,767	64,264	67,379
EBITDA	12,275	12,634	37,864	38,458
Depreciation and Amortization	4,627	4,598	13,901	13,740
Operating Income	7,648	8,036	23,963	24,718
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Income Before Income Taxes	7,648	8,036	23,963	24,718
Communications | Mobility | Operating Segments
Segment Reporting Information [Line Items]
Revenues	17,894	17,701	52,445	52,356
Operations and Support Expenses	10,182	9,948	29,083	29,511
EBITDA	7,712	7,753	23,362	22,845
Depreciation and Amortization	2,021	2,011	6,078	6,027
Operating Income	5,691	5,742	17,284	16,818
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Income Before Income Taxes	5,691	5,742	17,284	16,818
Communications | Entertainment Group | Operating Segments
Segment Reporting Information [Line Items]
Revenues	10,053	11,197	30,637	33,893
Operations and Support Expenses	7,997	8,797	23,618	25,839
EBITDA	2,056	2,400	7,019	8,054
Depreciation and Amortization	1,277	1,316	3,875	3,978
Operating Income	779	1,084	3,144	4,076
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Income Before Income Taxes	779	1,084	3,144	4,076
Communications | Business Wireline | Operating Segments
Segment Reporting Information [Line Items]
Revenues	6,340	6,503	19,046	19,588
Operations and Support Expenses	3,833	4,022	11,563	12,029
EBITDA	2,507	2,481	7,483	7,559
Depreciation and Amortization	1,329	1,271	3,948	3,735
Operating Income	1,178	1,210	3,535	3,824
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Income Before Income Taxes	1,178	1,210	3,535	3,824
WarnerMedia | Operating Segments
Segment Reporting Information [Line Items]
Revenues	7,514	8,350	22,176	25,990
Operations and Support Expenses	5,584	5,329	16,005	17,918
EBITDA	1,930	3,021	6,171	8,072
Depreciation and Amortization	171	165	501	425
Operating Income	1,759	2,856	5,670	7,647
Equity in Net Income (Loss) of Affiliates	11	15	30	137
Income Before Income Taxes	1,770	2,871	5,700	7,784
WarnerMedia | Eliminations and other
Segment Reporting Information [Line Items]
Revenues	146	191	(962)	845
Operations and Support Expenses	(171)	91	(882)	438
EBITDA	317	100	(80)	407
Depreciation and Amortization	32	25	97	69
Operating Income	285	75	(177)	338
Equity in Net Income (Loss) of Affiliates	40	20	65	70
Income Before Income Taxes	325	95	(112)	408
WarnerMedia | Turner | Operating Segments
Segment Reporting Information [Line Items]
Revenues	3,176	3,007	9,326	9,860
Operations and Support Expenses	2,088	1,460	5,145	5,813
EBITDA	1,088	1,547	4,181	4,047
Depreciation and Amortization	69	68	207	167
Operating Income	1,019	1,479	3,974	3,880
Equity in Net Income (Loss) of Affiliates	(6)	10	0	46
Income Before Income Taxes	1,013	1,489	3,974	3,926
WarnerMedia | Home Box Office | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,781	1,819	4,905	5,045
Operations and Support Expenses	1,694	1,072	4,236	3,124
EBITDA	87	747	669	1,921
Depreciation and Amortization	27	33	73	67
Operating Income	60	714	596	1,854
Equity in Net Income (Loss) of Affiliates	0	10	15	40
Income Before Income Taxes	60	724	611	1,894
WarnerMedia | Warner Bros. | Operating Segments
Segment Reporting Information [Line Items]
Revenues	2,411	3,333	8,907	10,240
Operations and Support Expenses	1,973	2,706	7,506	8,543
EBITDA	438	627	1,401	1,697
Depreciation and Amortization	43	39	124	122
Operating Income	395	588	1,277	1,575
Equity in Net Income (Loss) of Affiliates	(23)	(25)	(50)	(19)
Income Before Income Taxes	372	563	1,227	1,556
Latin America | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,396	1,730	4,218	5,205
Operations and Support Expenses	1,337	1,625	4,033	4,910
EBITDA	59	105	185	295
Depreciation and Amortization	250	284	773	868
Operating Income	(191)	(179)	(588)	(573)
Equity in Net Income (Loss) of Affiliates	14	13	26	25
Income Before Income Taxes	(177)	(166)	(562)	(548)
Latin America | Vrio | Operating Segments
Segment Reporting Information [Line Items]
Revenues	753	1,013	2,392	3,112
Operations and Support Expenses	675	851	2,119	2,598
EBITDA	78	162	273	514
Depreciation and Amortization	126	162	400	496
Operating Income	(48)	0	(127)	18
Equity in Net Income (Loss) of Affiliates	14	13	26	25
Income Before Income Taxes	(34)	13	(101)	43
Latin America | Mexico | Operating Segments
Segment Reporting Information [Line Items]
Revenues	643	717	1,826	2,093
Operations and Support Expenses	662	774	1,914	2,312
EBITDA	(19)	(57)	(88)	(219)
Depreciation and Amortization	124	122	373	372
Operating Income	(143)	(179)	(461)	(591)
Equity in Net Income (Loss) of Affiliates	0	0	0	0
Income Before Income Taxes	$ (143)	$ (179)	$ (461)	$ (591)