Subsequent Events (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 29, 2016	Dec. 31, 2017
Subsequent Event
Subsequent Event [Line Items]
Lease term	9 years
Letters of credit outstanding, amount	$ 1,000,000.0
Scenario, Forecast
Subsequent Event [Line Items]
Letter of credit provided to the landlord		$ 4,200,000