Segment Information - Operating Financial Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 32,796	$ 32,596	$ 65,777	$ 65,508
Operating Income	7,818	7,220	15,339	14,804
Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	4,998	5,277	10,359	11,037
Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	27,798	27,319	55,418	54,471
Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	3,209	3,194	6,416	6,390
Wireless service
Segment Reporting Information [Line Items]
Operating revenues	19,773	19,113	39,286	38,002
Consumer \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	2,896	2,886	5,792	5,775
Consumer \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	16,342	15,762	32,476	31,361
Business \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	855	847	1,700	1,700
Business \| Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	6,400	6,600	13,000	13,200
Business \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	313	308	624	615
Business \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	3,431	3,351	6,810	6,641
Operating Segments Excluding Intersegment Elimination
Segment Reporting Information [Line Items]
Operating revenues	32,163	31,981	64,535	64,274
Operating Segments Excluding Intersegment Elimination \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	24,872	24,506	49,877	49,314
Operating Segments Excluding Intersegment Elimination \| Consumer \| Service
Segment Reporting Information [Line Items]
Operating revenues	19,208	18,641	38,206	37,097
Operating Segments Excluding Intersegment Elimination \| Consumer \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	4,143	4,430	8,633	9,308
Operating Segments Excluding Intersegment Elimination \| Consumer \| Other
Segment Reporting Information [Line Items]
Operating revenues	1,521	1,435	3,038	2,909
Operating Segments Excluding Intersegment Elimination \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,291	7,475	14,658	14,960
Operating Segments Excluding Intersegment Elimination \| Business \| Enterprise and Public Sector
Segment Reporting Information [Line Items]
Operating revenues	3,545	3,784	7,132	7,571
Operating Segments Excluding Intersegment Elimination \| Business \| Business Markets and Other
Segment Reporting Information [Line Items]
Operating revenues	3,199	3,104	6,389	6,203
Operating Segments Excluding Intersegment Elimination \| Business \| Wholesale
Segment Reporting Information [Line Items]
Operating revenues	547	587	1,137	1,186
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	64	60	125	118
Intersegment Eliminations \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	55	52	107	101
Intersegment Eliminations \| Business
Segment Reporting Information [Line Items]
Operating revenues	9	8	18	17
Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	32,227	32,041	64,660	64,392
Operating Income	8,104	7,863	15,875	15,513
Operating Segments \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	24,927	24,558	49,984	49,415
Operating Income	7,604	7,330	14,976	14,429
Operating Segments \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,300	7,483	14,676	14,977
Operating Income	$ 500	$ 533	$ 899	$ 1,084