v3.20.2
Receivables and Expected Credit Losses - EIP Receivables (Details)
$ in Millions
 6 Months Ended
Jun. 30, 2020
USD ($)
segment
class
Jan. 01, 2020
USD ($)
Dec. 31, 2019
USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Portfolio segments | segment 2    
Customer classes | class 2    
Total EIP Receivables, net of unamortized imputed discounts $ 5,084   $ 4,582
Unamortized imputed discount (229)   (299)
EIP receivables, net of unamortized imputed discount 4,855   4,283
Allowance for credit losses (262)   (100)
Equipment installment plan receivables, net 4,593   4,183
Accounting Standards Update 2016-13 | Beginning balance adjustment due to implementation of the new credit loss standard      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Allowance for credit losses   $ (91)  
Equipment installment plan receivables, net of allowance for credit losses and imputed discount      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Equipment installment plan receivables, net 3,194   2,600
Equipment installment plan receivables due after one year, net of allowance for credit losses and imputed discount      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Equipment installment plan receivables, net $ 1,399   $ 1,583