Revenue Recognition (Revenue Categories) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 30,350	$ 30,043	$ 90,406	$ 89,398
Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	25,112	24,731	74,579	72,998
Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	16,580	15,899	49,034	46,663
Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	5,087	5,524	15,401	16,418
Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	2,667	2,429	7,755	7,177
Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	437	515	1,379	1,645
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	341	364	1,010	1,095
Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	5,238	5,312	15,827	16,400
Operating Segments
Disaggregation of Revenue [Line Items]
Total operating revenues	30,236	29,916	90,083	88,985
Operating Segments | Communications
Disaggregation of Revenue [Line Items]
Total operating revenues	29,244	29,131	87,241	86,702
Operating Segments | Communications | Mobility
Disaggregation of Revenue [Line Items]
Total operating revenues	20,692	20,278	61,589	60,279
Operating Segments | Communications | Mobility | Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	15,908	15,337	47,136	45,065
Operating Segments | Communications | Mobility | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	15,908	15,337	47,136	45,065
Operating Segments | Communications | Mobility | Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Mobility | Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Mobility | Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Mobility | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Mobility | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	4,784	4,941	14,453	15,214
Operating Segments | Communications | Business Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	5,221	5,668	15,831	16,903
Operating Segments | Communications | Business Wireline | Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	5,087	5,524	15,401	16,418
Operating Segments | Communications | Business Wireline | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Business Wireline | Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	5,087	5,524	15,401	16,418
Operating Segments | Communications | Business Wireline | Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Business Wireline | Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Business Wireline | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Business Wireline | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	134	144	430	485
Operating Segments | Communications | Consumer Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	3,331	3,185	9,821	9,520
Operating Segments | Communications | Consumer Wireline | Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	3,331	3,185	9,821	9,520
Operating Segments | Communications | Consumer Wireline | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Consumer Wireline | Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Communications | Consumer Wireline | Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	2,667	2,429	7,755	7,177
Operating Segments | Communications | Consumer Wireline | Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	368	427	1,147	1,332
Operating Segments | Communications | Consumer Wireline | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	296	329	919	1,011
Operating Segments | Communications | Consumer Wireline | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Latin America
Disaggregation of Revenue [Line Items]
Total operating revenues	992	785	2,842	2,283
Operating Segments | Latin America | Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	672	559	1,898	1,583
Operating Segments | Latin America | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	672	559	1,898	1,583
Operating Segments | Latin America | Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Latin America | Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Latin America | Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Latin America | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Operating Segments | Latin America | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	320	226	944	700
Corporate
Disaggregation of Revenue [Line Items]
Total operating revenues	114	127	323	413
Corporate | Total Service
Disaggregation of Revenue [Line Items]
Total operating revenues	114	126	323	412
Corporate | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	3	0	15
Corporate | Business service
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Corporate | Broadband
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Corporate | Legacy voice and data
Disaggregation of Revenue [Line Items]
Total operating revenues	69	88	232	313
Corporate | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	45	35	91	84
Corporate | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 0	$ 1	$ 0	$ 1