Commitments and Contingencies - Schedule of Future Minimum Payments under Non-Cancellable Operating and Capital Lease Agreements and Other Non-Cancellable Agreements (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Operating Leases
Remainder of 2018	$ 1,203
2019	4,647
2020	3,884
2021	4,109
2022	5,097
Thereafter	1,149
Total Minimum Lease Payments	20,089
Capital Leases
Remainder of 2018	9
2019	33
2020	33
2021	33
2022	33
Total Minimum Lease Payments	141
Less amounts representing interest	(13)
Present value of capital lease obligations	128
Less: Current portion	(25)	$ (21)
Capital leases, net of current portion	$ 103	$ 26