Property and Equipment - Asset Retirement Obligation (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
Dec. 31, 2019 |
|
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | |||||
| Asset retirement obligations, beginning of year | $ 659 | $ 609 | $ 609 | ||
| Fair value of liabilities acquired through Merger | 1,062 | 0 | |||
| Liabilities incurred | 6 | 35 | |||
| Liabilities settled | 0 | (2) | |||
| Accretion expense | 22 | 32 | |||
| Changes in estimated cash flows | 0 | (15) | |||
| Asset retirement obligations, end of period | $ 1,749 | 1,749 | 659 | ||
| Asset retirement costs capitalized, net | 1,100 | 1,100 | 159 | ||
| Non-cash impairment related to capitalized software development costs | 200 | $ 0 | 200 | $ 0 | |
| Other long-term liabilities | |||||
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | |||||
| Asset retirement obligations, beginning of year | 659 | ||||
| Asset retirement obligations, end of period | $ 1,749 | $ 1,749 | $ 659 | ||