v3.26.1
Segment Information - Operating Financial Information (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Operating revenues $ 34,253 $ 34,504 $ 68,693 $ 67,989
Depreciation and amortization expense 5,008 4,635 9,900 9,212
Total Operating Expenses 27,074 26,332 53,272 51,839
Operating Income 7,179 8,172 15,421 16,150
Service        
Segment Reporting [Line Items]        
Cost of wireless equipment 7,225 6,878 14,392 13,828
Wireless equipment        
Segment Reporting [Line Items]        
Operating revenues 5,024 6,255 10,705 11,653
Cost of wireless equipment 5,859 7,007 12,365 13,113
Operating Segments Excluding Intersegment Elimination | Service        
Segment Reporting [Line Items]        
Operating revenues 23,284 22,654 46,073 45,091
Operating Segments Excluding Intersegment Elimination | Wireless equipment        
Segment Reporting [Line Items]        
Operating revenues 5,024 6,255 10,705 11,653
Operating Segments Excluding Intersegment Elimination | Other        
Segment Reporting [Line Items]        
Operating revenues 5,008 4,631 10,042 9,335
Operating Segments Excluding Intersegment Elimination | Consumer | Service        
Segment Reporting [Line Items]        
Operating revenues 19,563 18,928 38,671 37,655
Operating Segments Excluding Intersegment Elimination | Consumer | Wireless equipment        
Segment Reporting [Line Items]        
Operating revenues 4,178 5,369 9,002 9,901
Operating Segments Excluding Intersegment Elimination | Consumer | Other        
Segment Reporting [Line Items]        
Operating revenues 2,427 2,277 4,876 4,562
Operating Segments Excluding Intersegment Elimination | Business | Service        
Segment Reporting [Line Items]        
Operating revenues 3,721 3,726 7,402 7,436
Operating Segments Excluding Intersegment Elimination | Business | Wireless equipment        
Segment Reporting [Line Items]        
Operating revenues 846 886 1,703 1,752
Operating Segments Excluding Intersegment Elimination | Business | Other        
Segment Reporting [Line Items]        
Operating revenues 2,581 2,354 5,166 4,773
Intersegment Eliminations        
Segment Reporting [Line Items]        
Operating revenues 81 81 160 162
Intersegment Eliminations | Consumer        
Segment Reporting [Line Items]        
Operating revenues 74 74 146 148
Intersegment Eliminations | Business        
Segment Reporting [Line Items]        
Operating revenues 7 7 14 14
Operating Segments        
Segment Reporting [Line Items]        
Operating revenues 33,397 33,621 66,980 66,241
Cost of wireless equipment 5,861 7,007 12,366 13,113
Centrally managed network and shared service costs 6,808 6,764 13,493 13,616
Depreciation and amortization expense 4,878 4,580 9,657 9,112
Other segment expenses 6,827 6,903 13,771 13,863
Total Operating Expenses 24,374 25,254 49,287 49,704
Operating Income 9,023 8,367 17,693 16,537
Operating Segments | Consumer        
Segment Reporting [Line Items]        
Operating revenues 26,242 26,648 52,695 52,266
Cost of wireless equipment 4,658 5,806 9,961 10,718
Centrally managed network and shared service costs 4,580 4,488 9,020 9,042
Depreciation and amortization expense 3,787 3,582 7,517 7,125
Other segment expenses 5,185 5,129 10,451 10,314
Total Operating Expenses 18,210 19,005 36,949 37,199
Operating Income 8,032 7,643 15,746 15,067
Operating Segments | Business        
Segment Reporting [Line Items]        
Operating revenues 7,155 6,973 14,285 13,975
Cost of wireless equipment 1,203 1,201 2,405 2,395
Centrally managed network and shared service costs 2,228 2,276 4,473 4,574
Depreciation and amortization expense 1,091 998 2,140 1,987
Other segment expenses 1,642 1,774 3,320 3,549
Total Operating Expenses 6,164 6,249 12,338 12,505
Operating Income $ 991 $ 724 $ 1,947 $ 1,470