Revenue from Contracts with Customers - Contract Costs (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
Mar. 31, 2020 |
Dec. 31, 2019 |
|
| Disaggregation of Revenue [Line Items] | ||||||
| Deferred incremental costs to obtain contracts | $ 939,000,000 | $ 939,000,000 | $ 906,000,000 | |||
| Average amortization period, deferred contract costs (in months) | 24 months | 24 months | ||||
| Amortization of deferred costs | $ 205,000,000 | $ 137,000,000 | $ 410,000,000 | $ 253,000,000 | ||
| Contract Liabilities | 845,000,000 | 845,000,000 | $ 560,000,000 | |||
| Impairment losses recognized on deferred contract cost assets | $ 0 | $ 0 | $ 0 | $ 0 | ||
| Sprint | ||||||
| Disaggregation of Revenue [Line Items] | ||||||
| Contract Liabilities | $ 1,700,000,000 | |||||