Segment Information - Operating Financial Information for Reportable Segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating Revenues	$ 134,788	$ 133,974	$ 136,835
Depreciation and amortization expense	17,892	17,624	17,099
Total Operating Expenses	106,102	111,097	106,368
Operating Income	28,686	22,877	30,467
Service
Segment Reporting Information [Line Items]
Cost of services and wireless equipment	27,997	28,100	28,637
Wireless equipment
Segment Reporting Information [Line Items]
Operating Revenues	23,217	24,322	27,210
Cost of services and wireless equipment	26,100	26,787	30,496
Service revenues and other
Segment Reporting Information [Line Items]
Operating Revenues	111,571	109,652	109,625
Fios Revenues
Segment Reporting Information [Line Items]
Operating Revenues	12,899	12,849	12,823
Fios Revenues | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	11,647	11,614	11,622
Fios Revenues | Business
Segment Reporting Information [Line Items]
Operating Revenues	1,252	1,235	1,201
Wireless Service
Segment Reporting Information [Line Items]
Operating Revenues	79,127	76,730	74,354
Wireless Service | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	65,374	63,358	61,509
Wireless Service | Business
Segment Reporting Information [Line Items]
Operating Revenues	13,753	13,372	12,845
Operating Segments Excluding Intersegment Elimination | Service
Segment Reporting Information [Line Items]
Operating Revenues	76,880	74,874	73,139
Operating Segments Excluding Intersegment Elimination | Service | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	76,880	74,874	73,139
Operating Segments Excluding Intersegment Elimination | Service | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Wireless equipment
Segment Reporting Information [Line Items]
Operating Revenues	19,598	20,645	23,168
Operating Segments Excluding Intersegment Elimination | Wireless equipment | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	19,598	20,645	23,168
Operating Segments Excluding Intersegment Elimination | Wireless equipment | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Other
Segment Reporting Information [Line Items]
Operating Revenues	6,213	5,898	6,996
Operating Segments Excluding Intersegment Elimination | Other | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	6,213	5,898	6,996
Operating Segments Excluding Intersegment Elimination | Other | Business
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Enterprise and Public Sector
Segment Reporting Information [Line Items]
Operating Revenues	14,218	15,076	15,692
Operating Segments Excluding Intersegment Elimination | Enterprise and Public Sector | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Enterprise and Public Sector | Business
Segment Reporting Information [Line Items]
Operating Revenues	14,218	15,076	15,692
Operating Segments Excluding Intersegment Elimination | Business Markets and Other
Segment Reporting Information [Line Items]
Operating Revenues	13,081	12,697	12,753
Operating Segments Excluding Intersegment Elimination | Business Markets and Other | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Business Markets and Other | Business
Segment Reporting Information [Line Items]
Operating Revenues	13,081	12,697	12,753
Operating Segments Excluding Intersegment Elimination | Wholesale
Segment Reporting Information [Line Items]
Operating Revenues	2,196	2,313	2,584
Operating Segments Excluding Intersegment Elimination | Wholesale | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0
Operating Segments Excluding Intersegment Elimination | Wholesale | Business
Segment Reporting Information [Line Items]
Operating Revenues	2,196	2,313	2,584
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	249	245	246
Intersegment Eliminations | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	213	209	203
Intersegment Eliminations | Business
Segment Reporting Information [Line Items]
Operating Revenues	36	36	43
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues	132,435	131,748	134,578
Centrally managed network and shared service costs	27,981	28,086	27,837
Depreciation and amortization expense	17,859	17,565	17,028
Other segment expenses	28,953	28,234	27,740
Total Operating Expenses	100,893	100,671	103,101
Operating Income	31,542	31,077	31,477
Operating Segments | Consumer
Segment Reporting Information [Line Items]
Operating Revenues	102,904	101,626	103,506
Centrally managed network and shared service costs	17,781	17,496	16,997
Depreciation and amortization expense	13,552	13,077	12,716
Other segment expenses	20,828	20,215	19,813
Total Operating Expenses	73,420	72,615	74,660
Operating Income	29,484	29,011	28,846
Operating Segments | Business
Segment Reporting Information [Line Items]
Operating Revenues	29,531	30,122	31,072
Centrally managed network and shared service costs	10,200	10,590	10,840
Depreciation and amortization expense	4,307	4,488	4,312
Other segment expenses	8,125	8,019	7,927
Total Operating Expenses	27,473	28,056	28,441
Operating Income	2,058	2,066	2,631
Operating Segments | Wireless equipment
Segment Reporting Information [Line Items]
Cost of services and wireless equipment	26,100	26,786	30,496
Operating Segments | Wireless equipment | Consumer
Segment Reporting Information [Line Items]
Cost of services and wireless equipment	21,259	21,827	25,134
Operating Segments | Wireless equipment | Business
Segment Reporting Information [Line Items]
Operating Revenues	3,600	3,700	4,000
Cost of services and wireless equipment	4,841	4,959	5,362
Operating Segments | Service revenues and other | Business
Segment Reporting Information [Line Items]
Operating Revenues	$ 25,900	$ 26,400	$ 27,000