Stockholders' Equity (Deficit) - Restricted Stock Units - Additional Information (Details) $ in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2018
USD ($)
| |
| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
| Unrecognized stock compensation expense | $ 38.5 |
| Expected weighted average period to recognize unrecognized stock compensation expense | 2 years 1 month 9 days |
| Restricted Stock Units | |
| Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
| Grant-date fair value of restricted stock units granted | $ 184.7 |
| Unrecognized stock compensation expense | $ 167.5 |
| Expected weighted average period to recognize unrecognized stock compensation expense | 3 years 3 months 14 days |