v3.25.4
Debt (Summary Of Long-Term Debt Of AT&T And Its Subsidiaries) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Debt Instrument [Line Items]    
Carrying amount of notes and debentures $ 144,311 $ 131,835
Unamortized (discount) premium – net (9,193) (9,340)
Unamortized issuance costs (400) (379)
Total notes and debentures 134,718 122,116
Finance lease obligations 1,382 1,416
Total long-term debt, including current maturities 136,100 123,532
Current maturities of long-term debt (9,011) (5,089)
Total long-term debt 127,089 118,443
Fair value of interest rate swaps recorded in debt    
Debt Instrument [Line Items]    
Carrying amount of notes and debentures 3 6
Notes And Debentures Maturing Through 2033 [Member] | Notes and debentures    
Debt Instrument [Line Items]    
Carrying amount of notes and debentures $ 22,240 21,860
Notes And Debentures Maturing Through 2033 [Member] | Notes and debentures | Minimum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 0.00%  
Notes And Debentures Maturing Through 2033 [Member] | Notes and debentures | Maximum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 2.99%  
Notes And Debentures Maturing through 2061 | Notes and debentures    
Debt Instrument [Line Items]    
Carrying amount of notes and debentures $ 89,379 83,725
Notes And Debentures Maturing through 2061 | Notes and debentures | Minimum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 3.00%  
Notes And Debentures Maturing through 2061 | Notes and debentures | Maximum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 4.99%  
Notes And Debentures Maturing through 2095 | Notes and debentures    
Debt Instrument [Line Items]    
Carrying amount of notes and debentures $ 29,165 22,679
Notes And Debentures Maturing through 2095 | Notes and debentures | Minimum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 5.00%  
Notes And Debentures Maturing through 2095 | Notes and debentures | Maximum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 6.99%  
Notes And Debentures Maturing through 2097 | Notes and debentures    
Debt Instrument [Line Items]    
Carrying amount of notes and debentures $ 3,524 $ 3,565
Notes And Debentures Maturing through 2097 | Notes and debentures | Minimum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 7.00%  
Notes And Debentures Maturing through 2097 | Notes and debentures | Maximum    
Debt Instrument [Line Items]    
Debt instrument - stated percentage rate 8.75%