Segment Information - Operating Financial Information (Detail) - 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]
Operating revenues	$ 33,336	$ 34,241	$ 98,844	$ 101,584
Operating Income	7,473	7,894	22,277	23,242
Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	5,813	6,575	16,850	19,585
Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	27,523	27,666	81,994	81,999
Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	3,205	3,206	9,595	9,605
Wireless service
Segment Reporting Information [Line Items]
Operating revenues	19,330	18,790	57,332	55,550
Consumer \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	2,897	2,902	8,672	8,708
Consumer \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	15,963	15,517	47,324	45,970
Business \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	911	1,000	2,600	2,900
Business \| Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	6,600	6,800	19,900	20,200
Business \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	308	304	923	897
Business \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	3,367	3,273	10,008	9,580
Operating Segments Excluding Intersegment Elimination
Segment Reporting Information [Line Items]
Operating revenues	32,720	33,615	96,994	99,721
Operating Segments Excluding Intersegment Elimination \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	25,202	25,788	74,516	76,583
Operating Segments Excluding Intersegment Elimination \| Consumer \| Service
Segment Reporting Information [Line Items]
Operating revenues	18,850	18,421	55,947	54,696
Operating Segments Excluding Intersegment Elimination \| Consumer \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	4,902	5,558	14,210	16,640
Operating Segments Excluding Intersegment Elimination \| Consumer \| Other
Segment Reporting Information [Line Items]
Operating revenues	1,450	1,809	4,359	5,247
Operating Segments Excluding Intersegment Elimination \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,518	7,827	22,478	23,138
Operating Segments Excluding Intersegment Elimination \| Business \| Enterprise and Public Sector
Segment Reporting Information [Line Items]
Operating revenues	3,786	3,940	11,357	11,784
Operating Segments Excluding Intersegment Elimination \| Business \| Business Markets and Other
Segment Reporting Information [Line Items]
Operating revenues	3,180	3,231	9,383	9,428
Operating Segments Excluding Intersegment Elimination \| Business \| Wholesale
Segment Reporting Information [Line Items]
Operating revenues	552	656	1,738	1,926
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	64	62	182	187
Intersegment Eliminations \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	55	52	156	153
Intersegment Eliminations \| Business
Segment Reporting Information [Line Items]
Operating revenues	9	10	26	34
Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	32,784	33,677	97,176	99,908
Operating Income	8,086	8,047	23,599	23,864
Operating Segments \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	25,257	25,840	74,672	76,736
Operating Income	7,547	7,349	21,976	21,818
Operating Segments \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,527	7,837	22,504	23,172
Operating Income	$ 539	$ 698	$ 1,623	$ 2,046