Subsequent Event - Additional Information (Details) - Subsequent Event [Member]	Feb. 07, 2019 USD ($) Employee
Subsequent Event [Line Items]
Reduction in headcount of employees | Employee	30
One-Time Costs [Member] | Minimum [Member]
Subsequent Event [Line Items]
Expected employee termination benefits	$ 1,500,000
One-Time Costs [Member] | Maximum [Member]
Subsequent Event [Line Items]
Expected employee termination benefits	$ 2,000,000