Segment Information (Summary Of Operating Revenues And Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Revenues	$ 30,350	$ 30,043	$ 90,406	$ 89,398
Operations and Support Expenses	19,863	19,517	58,205	59,467
EBITDA	10,487	10,526	32,201	29,931
Depreciation and Amortization	4,705	4,514	14,011	13,426
Operating Income (Loss)	5,782	6,012	18,190	16,505
Operating Segments
Segment Reporting Information [Line Items]
Revenues	30,236	29,916	90,083	88,985
Operations and Support Expenses	18,458	18,642	55,492	56,156
EBITDA	11,778	11,274	34,591	32,829
Depreciation and Amortization	4,534	4,348	13,496	12,917
Operating Income (Loss)	7,244	6,926	21,095	19,912
DTV-related retained costs
Segment Reporting Information [Line Items]
Revenues	0	0	0	8
Operations and Support Expenses	167	235	514	634
EBITDA	(167)	(235)	(514)	(626)
Depreciation and Amortization	144	139	440	408
Operating Income (Loss)	(311)	(374)	(954)	(1,034)
Parent Administration Support
Segment Reporting Information [Line Items]
Revenues	(1)	(6)	(13)	(24)
Operations and Support Expenses	333	317	1,039	1,005
EBITDA	(334)	(323)	(1,052)	(1,029)
Depreciation and Amortization	1	2	4	12
Operating Income (Loss)	(335)	(325)	(1,056)	(1,041)
Securitization Fees
Segment Reporting Information [Line Items]
Revenues	25	15	61	48
Operations and Support Expenses	164	103	439	263
EBITDA	(139)	(88)	(378)	(215)
Depreciation and Amortization	0	0	0	0
Operating Income (Loss)	(139)	(88)	(378)	(215)
Value Portfolio
Segment Reporting Information [Line Items]
Revenues	90	118	275	381
Operations and Support Expenses	25	32	77	106
EBITDA	65	86	198	275
Depreciation and Amortization	5	9	16	29
Operating Income (Loss)	60	77	182	246
Total Corporate
Segment Reporting Information [Line Items]
Revenues	114	127	323	413
Operations and Support Expenses	689	687	2,069	2,008
EBITDA	(575)	(560)	(1,746)	(1,595)
Depreciation and Amortization	150	150	460	449
Operating Income (Loss)	(725)	(710)	(2,206)	(2,044)
Certain significant items
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operations and Support Expenses	716	188	644	1,303
EBITDA	(716)	(188)	(644)	(1,303)
Depreciation and Amortization	21	16	55	60
Operating Income (Loss)	(737)	(204)	(699)	(1,363)
Communications | Operating Segments
Segment Reporting Information [Line Items]
Revenues	29,244	29,131	87,241	86,702
Operations and Support Expenses	17,621	17,958	53,096	54,120
EBITDA	11,623	11,173	34,145	32,582
Depreciation and Amortization	4,350	4,184	12,952	12,423
Operating Income (Loss)	7,273	6,989	21,193	20,159
Communications | Mobility | Operating Segments
Segment Reporting Information [Line Items]
Revenues	20,692	20,278	61,589	60,279
Operations and Support Expenses	11,795	12,010	35,587	36,198
EBITDA	8,897	8,268	26,002	24,081
Depreciation and Amortization	2,134	2,042	6,355	6,118
Operating Income (Loss)	6,763	6,226	19,647	17,963
Communications | Business Wireline | Operating Segments
Segment Reporting Information [Line Items]
Revenues	5,221	5,668	15,831	16,903
Operations and Support Expenses	3,526	3,705	10,699	11,199
EBITDA	1,695	1,963	5,132	5,704
Depreciation and Amortization	1,345	1,342	4,008	3,954
Operating Income (Loss)	350	621	1,124	1,750
Communications | Consumer Wireline | Operating Segments
Segment Reporting Information [Line Items]
Revenues	3,331	3,185	9,821	9,520
Operations and Support Expenses	2,300	2,243	6,810	6,723
EBITDA	1,031	942	3,011	2,797
Depreciation and Amortization	871	800	2,589	2,351
Operating Income (Loss)	160	142	422	446
Latin America - Mexico | Operating Segments
Segment Reporting Information [Line Items]
Revenues	992	785	2,842	2,283
Operations and Support Expenses	837	684	2,396	2,036
EBITDA	155	101	446	247
Depreciation and Amortization	184	164	544	494
Operating Income (Loss)	(29)	(63)	(98)	(247)
Total Corporate and Other
Segment Reporting Information [Line Items]
Revenues	114	127	323	413
Operations and Support Expenses	1,405	875	2,713	3,311
EBITDA	(1,291)	(748)	(2,390)	(2,898)
Depreciation and Amortization	171	166	515	509
Operating Income (Loss)	$ (1,462)	$ (914)	$ (2,905)	$ (3,407)