Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Commitments Contingencies And Litigation [Line Items]
Lease expense	$ 0.1	$ 0.1	$ 0.1	$ 0.2
Minimum
Commitments Contingencies And Litigation [Line Items]
Employee Termination Expenses			0.4
Maximum
Commitments Contingencies And Litigation [Line Items]
Employee Termination Expenses			$ 0.7