v3.26.3
Wireless Licenses, Goodwill and Other Intangible Assets - Composition of Other Intangible Assets, Net (Detail) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Intangible Asset, Finite-Lived [Line Items]    
Gross Amount $ 38,652 $ 35,668
Accumulated Amortization (26,650) (25,210)
Net Amount 12,002 10,458
Customer Lists    
Intangible Asset, Finite-Lived [Line Items]    
Gross Amount 7,034 4,243
Accumulated Amortization (3,651) (3,116)
Net Amount $ 3,383 1,127
Customer Lists | Minimum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 2 years  
Customer Lists | Maximum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 13 years  
Non-network internal-use software    
Intangible Asset, Finite-Lived [Line Items]    
Gross Amount $ 28,886 28,749
Accumulated Amortization (21,040) (20,301)
Net Amount $ 7,846 8,448
Non-network internal-use software | Minimum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 3 years  
Non-network internal-use software | Maximum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 7 years  
Other    
Intangible Asset, Finite-Lived [Line Items]    
Gross Amount $ 2,732 2,676
Accumulated Amortization (1,959) (1,793)
Net Amount $ 773 $ 883
Other | Minimum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 3 years  
Other | Maximum    
Intangible Asset, Finite-Lived [Line Items]    
Other intangible asset, useful life 25 years