Segment Information - Operating Financial Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 32,981	$ 32,912
Operating Income	7,521	7,584
Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	5,361	5,760
Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	27,620	27,152
Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	3,207	3,196
Wireless service
Segment Reporting Information [Line Items]
Operating revenues	19,513	18,889
Consumer \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	2,896	2,889
Consumer \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	16,134	15,599
Business \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	871	882
Business \| Service revenues and other
Segment Reporting Information [Line Items]
Operating revenues	6,500	6,600
Business \| Fios revenues
Segment Reporting Information [Line Items]
Operating revenues	311	307
Business \| Wireless service
Segment Reporting Information [Line Items]
Operating revenues	3,379	3,290
Operating Segments Excluding Intersegment Elimination
Segment Reporting Information [Line Items]
Operating revenues	32,372	32,293
Operating Segments Excluding Intersegment Elimination \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	25,005	24,808
Operating Segments Excluding Intersegment Elimination \| Consumer \| Service
Segment Reporting Information [Line Items]
Operating revenues	18,998	18,456
Operating Segments Excluding Intersegment Elimination \| Consumer \| Wireless equipment
Segment Reporting Information [Line Items]
Operating revenues	4,490	4,878
Operating Segments Excluding Intersegment Elimination \| Consumer \| Other
Segment Reporting Information [Line Items]
Operating revenues	1,517	1,474
Operating Segments Excluding Intersegment Elimination \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,367	7,485
Operating Segments Excluding Intersegment Elimination \| Business \| Enterprise and Public Sector
Segment Reporting Information [Line Items]
Operating revenues	3,587	3,787
Operating Segments Excluding Intersegment Elimination \| Business \| Business Markets and Other
Segment Reporting Information [Line Items]
Operating revenues	3,190	3,099
Operating Segments Excluding Intersegment Elimination \| Business \| Wholesale
Segment Reporting Information [Line Items]
Operating revenues	590	599
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	61	58
Intersegment Eliminations \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	52	49
Intersegment Eliminations \| Business
Segment Reporting Information [Line Items]
Operating revenues	9	9
Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	32,433	32,351
Operating Income	7,771	7,650
Operating Segments \| Consumer
Segment Reporting Information [Line Items]
Operating revenues	25,057	24,857
Operating Income	7,372	7,099
Operating Segments \| Business
Segment Reporting Information [Line Items]
Operating revenues	7,376	7,494
Operating Income	$ 399	$ 551