v3.21.2
Revenue from Contracts with Customers (Tables)
 6 Months Ended
Jun. 30, 2021
Revenue from Contract with Customer [Abstract]  
Schedule of Disaggregation of Revenue Postpaid service revenues, including postpaid phone revenues and postpaid other revenues, were as follows:
Three Months Ended June 30,Six Months Ended June 30,
(in millions)2021202020212020
Postpaid service revenues
Postpaid phone revenues$9,667 $9,341 $19,150 $14,918 
Postpaid other revenues825 618 1,645 928 
Total postpaid service revenues$10,492 $9,959 $20,795 $15,846 
Equipment revenues from the lease of mobile communication devices were as follows:
Three Months Ended June 30,Six Months Ended June 30,
(in millions)2021202020212020
Equipment revenues from the lease of mobile communication devices$914 $1,421 $1,955 $1,586 
Schedule of Contract Liability and Receivable Balances The contract asset and contract liability balances from contracts with customers as of December 31, 2020 and June 30, 2021, were as follows:
(in millions)Contract AssetsContract Liabilities
Balance as of December 31, 2020$278 $824 
Balance as of June 30, 2021267 789 
Change$(11)$(35)
Revenues for the three and six months ended June 30, 2021 and 2020 include the following:
Three Months Ended June 30,Six Months Ended June 30,
(in millions)2021202020212020
Amounts included in the beginning of year contract liability balance$41 $10 $724 $538