v3.25.4
Debt - Narrative (Details)
12 Months Ended
Apr. 01, 2020
USD ($)
instrument
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Feb. 05, 2026
USD ($)
Jan. 22, 2026
USD ($)
Jan. 12, 2026
USD ($)
Jan. 05, 2026
USD ($)
Aug. 29, 2025
USD ($)
Mar. 17, 2025
USD ($)
Jan. 31, 2025
USD ($)
Jul. 25, 2023
USD ($)
Debt Instrument [Line Items]                      
Effective interest rate   4.20% 4.10%                
Weighted-average debt outstanding during period   $ 83,000,000,000 $ 78,300,000,000                
Principal outstanding   13,827,000,000                  
Debt instrument, repurchased face amount   1,199,000,000                  
Proceeds from loan facility   86,282,000,000 78,265,000,000                
Short-term debt   5,135,000,000 4,068,000,000                
Letters of credit, amount outstanding   116,000,000 152,000,000                
Spectrum Financing Special Purpose Entity                      
Debt Instrument [Line Items]                      
Lease payments (per month) $ 165,000,000                    
Sprint                      
Debt Instrument [Line Items]                      
Total outstanding obligation   827,000,000 1,300,000,000                
Revolving Credit Facility                      
Debt Instrument [Line Items]                      
Credit facility outstanding balance   0 0                
Senior Notes                      
Debt Instrument [Line Items]                      
Principal outstanding   10,827,000,000                  
Senior Notes | Sprint                      
Debt Instrument [Line Items]                      
Principal outstanding 3,900,000,000                    
Line of Credit | Revolving Credit Facility                      
Debt Instrument [Line Items]                      
Financing commitment, amount   7,500,000,000                  
Line of Credit | Revolving Credit Facility | Subsequent Event                      
Debt Instrument [Line Items]                      
Financing commitment, amount             $ 10,000,000,000        
Line of Credit | Letter of Credit                      
Debt Instrument [Line Items]                      
Financing commitment, amount   1,500,000,000                  
Line of Credit | Bridge Loan                      
Debt Instrument [Line Items]                      
Financing commitment, amount   500,000,000                  
ABS Notes                      
Debt Instrument [Line Items]                      
Principal outstanding   $ 1,000,000,000                  
Expected weighted average life   2 years 6 months                  
Payable term   2 years                  
Proceeds from loan facility   $ 2,000,000,000                  
Gross EIP receivables   2,600,000,000                  
Commercial Paper                      
Debt Instrument [Line Items]                      
Financing commitment, amount                     $ 2,000,000,000
Short-term debt   0 $ 0                
Loans Payable                      
Debt Instrument [Line Items]                      
Principal outstanding   2,000,000,000                  
Financing commitment, amount   $ 1,000,000,000                  
5.000% Senior Notes due 2036 | Subsequent Event                      
Debt Instrument [Line Items]                      
Principal outstanding           $ 1,200,000,000          
Interest rate, stated percentage           5.00%          
5.850% Senior Notes due 2056 | Subsequent Event                      
Debt Instrument [Line Items]                      
Principal outstanding           $ 850,000,000          
Interest rate, stated percentage           5.85%          
4.750% Senior Notes due 2028 | Senior Notes                      
Debt Instrument [Line Items]                      
Interest rate, stated percentage   4.75%                  
4.750% Senior Notes due 2028 | Senior Notes | Subsequent Event                      
Debt Instrument [Line Items]                      
Interest rate, stated percentage         4.75%            
Debt instrument, repurchased face amount         $ 3,000,000,000            
3.360% Senior Secured Series 2016-1 A-1 Notes due 2021 | Senior Notes | Sprint                      
Debt Instrument [Line Items]                      
Principal outstanding $ 3,500,000,000                    
Interest rate, stated percentage 3.36%                    
Payable term 5 years                    
Securitization program amount $ 7,000,000,000                    
Number of instruments | instrument 2                    
4.738% Series 2018-1 A-1 Notes due 2025 | Sprint                      
Debt Instrument [Line Items]                      
Principal outstanding $ 2,100,000,000                    
4.738% Series 2018-1 A-1 Notes due 2025 | Senior Notes                      
Debt Instrument [Line Items]                      
Interest rate, stated percentage   4.738%                  
5.200% Senior Notes due 2033 | Sprint                      
Debt Instrument [Line Items]                      
Short-term debt   $ 368,000,000                  
5.200% Senior Notes due 2033 | Senior Notes | Sprint                      
Debt Instrument [Line Items]                      
Principal outstanding   $ 1,800,000,000                  
5.152% Series 2018-1 A-2 Notes due 2028 | Senior Notes                      
Debt Instrument [Line Items]                      
Interest rate, stated percentage   5.152%                  
4.927% ECA Facility due March 2036 | Loans Payable                      
Debt Instrument [Line Items]                      
Principal outstanding                 $ 1,000,000,000    
Interest rate, stated percentage                 4.927%    
Financing commitment, amount                   $ 1,000,000,000.0  
ECA Facility due November 2036 | Loans Payable                      
Debt Instrument [Line Items]                      
Financing commitment, amount               $ 1,000,000,000      
Notes Payable, Other Payables | Subsequent Event                      
Debt Instrument [Line Items]                      
Principal outstanding       $ 1,000,000,000              
Minimum | Senior Secured Notes Issued in 2021 | Senior Notes                      
Debt Instrument [Line Items]                      
Term preceding maturity date   1 month                  
Maximum | Senior Secured Notes Issued in 2021 | Senior Notes                      
Debt Instrument [Line Items]                      
Term preceding maturity date   3 years