v3.26.1
Sales of Certain Receivables - Schedule of Factoring Arrangement (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]    
Other current liabilities $ 2,322 $ 2,575
Other long-term liabilities 3,993 3,794
Factoring and EIP Securitization Arrangement | Variable Interest Entity, Primary Beneficiary    
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]    
Derecognized net service accounts receivable and EIP receivables 1,669 1,651
Other current liabilities 379 397
Other long-term liabilities 13 13
Net cash proceeds since inception 1,352 1,372
Of which:    
Change in net cash proceeds during the year-to-date period (20) (96)
Net cash proceeds funded by reinvested collections 1,372 1,468
Factoring and EIP Securitization Arrangement | Variable Interest Entity, Primary Beneficiary | Other current liabilities - of which, recourse guarantee    
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]    
Carrying amounts of deferred purchase price assets 119 117
Factoring and EIP Securitization Arrangement | Variable Interest Entity, Primary Beneficiary | Other long-term liabilities - of which, recourse guarantee    
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]    
Carrying amounts of deferred purchase price assets $ 13 $ 13