Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Maturities of Operating Lease Liabilities [Abstract]
2019 (remaining three months)	$ 2,006
2020	3,657
2021	3,306
2022	1,844
Total lease payments	10,813
Less: Amount representing imputed interest	(823)
Present value of lease liabilities	9,990
Less: Current portion of lease liabilities	(4,294)	$ 0	[1]
Non-current portion of lease liabilities	5,696	0	[1]
Maturities of Finance Lease Liabilities [Abstract]
2019 (remaining three months)	278
2020	552
2021	12
2022	0
Total lease payments	842
Less: Amount representing imputed interest	(29)
Present value of lease liabilities	813
Less: Current portion of lease liabilities	(777)	$ (866)
Non-current portion of lease liabilities	$ 36

[1] Derived from the Company’s audited consolidated financial statements as of December 31, 2018.