Redeemable Convertible Preferred Stock, Common Stock, and Equity (Deficit) - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based compensation expense | $ 4,596 | $ 172 | $ 137 |
| Operations and support | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based compensation expense | 454 | 15 | 30 |
| Sales and marketing | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based compensation expense | 242 | 9 | 9 |
| Research and development | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based compensation expense | 2,958 | 65 | 25 |
| General and administrative | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-based compensation expense | $ 942 | $ 83 | $ 73 |