v3.25.1
Receivables and Related Allowance for Credit Losses - Schedule of Unamortized Imputed Discount and Allowance for Credit Losses for Equipment Installment Plan Receivables (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward]    
Allowance for credit losses and imputed discount, beginning of period $ 990 $ 934
Bad debt expense 323 282
Write-offs (324) (282)
Change in imputed discount on short-term and long-term EIP receivables 36 31
Impact on the imputed discount from sales of EIP receivables (42) (47)
Allowance for credit losses and imputed discount, end of period 983 918
Accounts Receivable Allowance    
Financing Receivable, Allowance for Credit Loss [Roll Forward]    
Allowance for credit losses and imputed discount, beginning of period 176 161
Bad debt expense 165 132
Write-offs (166) (132)
Allowance for credit losses and imputed discount, end of period 175 161
EIP Receivables Allowance    
Financing Receivable, Allowance for Credit Loss [Roll Forward]    
Allowance for credit losses and imputed discount, beginning of period 814 773
Bad debt expense 158 150
Write-offs (158) (150)
Change in imputed discount on short-term and long-term EIP receivables 36 31
Impact on the imputed discount from sales of EIP receivables (42) (47)
Allowance for credit losses and imputed discount, end of period $ 808 $ 757