v3.25.4
Wireless Licenses, Goodwill and Other Intangible Assets - Composition of Other Intangible Assets, Net (Detail) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]    
Gross Amount $ 35,668 $ 35,042
Accumulated Amortization (25,210) (23,913)
Net Amount 10,458 11,129
Customer lists    
Finite-Lived Intangible Assets [Line Items]    
Gross Amount 4,243 4,242
Accumulated Amortization (3,116) (2,629)
Net Amount $ 1,127 1,613
Customer lists | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 6 years  
Customer lists | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 13 years  
Non-Network Internal-Use Software    
Finite-Lived Intangible Assets [Line Items]    
Gross Amount $ 28,749 28,136
Accumulated Amortization (20,301) (19,743)
Net Amount $ 8,448 8,393
Non-Network Internal-Use Software | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 3 years  
Non-Network Internal-Use Software | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 7 years  
Other    
Finite-Lived Intangible Assets [Line Items]    
Gross Amount $ 2,676 2,664
Accumulated Amortization (1,793) (1,541)
Net Amount $ 883 $ 1,123
Other | Minimum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 4 years  
Other | Maximum    
Finite-Lived Intangible Assets [Line Items]    
Useful life for finite-lived intangible assets, years 25 years