Segment Information - Operating Financial Information for Reportable Segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenues	$ 133,613	$ 128,292	$ 131,868
Selling, general and administrative expense	28,658	31,573	29,896
Depreciation and amortization expense	16,206	16,720	16,682
Total Operating Expenses	101,165	99,494	101,490
Operating Income	32,448	28,798	30,378
Service
Segment Reporting Information [Line Items]
Cost of services and equipment	31,234	31,401	31,772
Wireless equipment
Segment Reporting Information [Line Items]
Operating Revenues	23,164	18,420	21,563
Cost of services and equipment	25,067	19,800	22,954
Wireless equipment | Business
Segment Reporting Information [Line Items]
Operating Revenues	3,400	2,900	3,500
Service revenues and other
Segment Reporting Information [Line Items]
Operating Revenues	110,449	109,872	110,305
Service revenues and other | Business
Segment Reporting Information [Line Items]
Operating Revenues	27,700	28,100	27,900
Wireless Service
Segment Reporting Information [Line Items]
Operating Revenues	68,469	65,410	64,979
Wireless Service | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	56,103	53,605	53,791
Wireless Service | Business
Segment Reporting Information [Line Items]
Operating Revenues	12,366	11,805	11,188
Fios Revenues
Segment Reporting Information [Line Items]
Operating Revenues	12,694	12,139	12,142
Fios Revenues | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	11,558	11,082	11,175
Fios Revenues | Business
Segment Reporting Information [Line Items]
Operating Revenues	1,136	1,057	967
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	297	311	301
Intersegment Eliminations | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	228	241	240
Intersegment Eliminations | Business
Segment Reporting Information [Line Items]
Operating Revenues	69	70	61
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues	126,342	119,495	122,499
Selling, general and administrative expense	24,886	25,316	24,827
Depreciation and amortization expense	15,763	15,481	15,458
Total Operating Expenses	92,950	86,866	89,776
Operating Income	33,392	32,629	32,723
Operating Segments | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	95,300	88,533	91,056
Selling, general and administrative expense	16,562	16,936	16,639
Depreciation and amortization expense	11,679	11,395	11,353
Total Operating Expenses	65,345	59,677	62,095
Operating Income	29,955	28,856	28,961
Operating Segments | Business
Segment Reporting Information [Line Items]
Operating Revenues	31,042	30,962	31,443
Selling, general and administrative expense	8,324	8,380	8,188
Depreciation and amortization expense	4,084	4,086	4,105
Total Operating Expenses	27,605	27,189	27,681
Operating Income	3,437	3,773	3,762
Operating Segments | Service
Segment Reporting Information [Line Items]
Operating Revenues	67,723	64,884	65,384
Cost of services and equipment	27,234	26,269	26,539
Operating Segments | Service | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	67,723	64,884	65,384
Cost of services and equipment	16,581	15,610	15,884
Operating Segments | Service | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Cost of services and equipment	10,653	10,659	10,655
Operating Segments | Wireless equipment
Segment Reporting Information [Line Items]
Operating Revenues	19,781	15,492	18,048
Cost of services and equipment	25,067	19,800	22,952
Operating Segments | Wireless equipment | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	19,781	15,492	18,048
Cost of services and equipment	20,523	15,736	18,219
Operating Segments | Wireless equipment | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Cost of services and equipment	4,544	4,064	4,733
Operating Segments | Other
Segment Reporting Information [Line Items]
Operating Revenues	7,568	7,916	7,384
Operating Segments | Other | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	7,568	7,916	7,384
Operating Segments | Other | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments | Small and Medium Business
Segment Reporting Information [Line Items]
Operating Revenues	11,751	11,112	11,447
Operating Segments | Small and Medium Business | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments | Small and Medium Business | Business
Segment Reporting Information [Line Items]
Operating Revenues	11,751	11,112	11,447
Operating Segments | Global Enterprise
Segment Reporting Information [Line Items]
Operating Revenues	10,218	10,405	10,815
Operating Segments | Global Enterprise | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments | Global Enterprise | Business
Segment Reporting Information [Line Items]
Operating Revenues	10,218	10,405	10,815
Operating Segments | Public Sector and Other
Segment Reporting Information [Line Items]
Operating Revenues	6,324	6,362	5,922
Operating Segments | Public Sector and Other | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments | Public Sector and Other | Business
Segment Reporting Information [Line Items]
Operating Revenues	6,324	6,362	5,922
Operating Segments | Wholesale
Segment Reporting Information [Line Items]
Operating Revenues	2,680	3,013	3,198
Operating Segments | Wholesale | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments | Wholesale | Business
Segment Reporting Information [Line Items]
Operating Revenues	$ 2,680	$ 3,013	$ 3,198