v3.24.0.1
Summary of Significant Accounting Policies - Narrative (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2023
USD ($)
reporting_unit
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Sep. 06, 2023
USD ($)
Sep. 08, 2022
USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Device upgrade period 18 months        
Number of reporting units | reporting_unit 1        
Term of contract 1 month        
Federal Universal Service Fund and other fees $ 317 $ 185 $ 216    
Average amortization period, deferred contract costs (in months) 24 months        
Advertising expense $ 2,500 $ 2,300 $ 2,200    
2022 Stock Repurchase Program          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Stock repurchase program, authorized amount         $ 14,000
2023-2024 Stockholder Return Program          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Stock repurchase program, authorized amount       $ 19,000  
Sprint          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Total term of agreement 30 years        
Sprint | Spectrum Licenses          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Fixed period 15 years        
Minimum | Sprint          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Agreements with educational and certain non-profit institutions, term 5 years        
Minimum | EIP Securitization Arrangement          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Equipment installment plan, maximum payment term 24 months        
Maximum | Sprint          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Agreements with educational and certain non-profit institutions, term 10 years