Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Operating leases
Operating lease right-of-use assets	$ 8,504	$ 10,100	$ 0
Operating lease liabilities (current)	4,262		0
Operating lease liabilities (net of current portion)	6,055		0
Total operating lease liabilities	$ 10,317	$ 12,300
Weighted average remaining lease term	3 years 1 month 6 days
Weighted average discount rate	7.10%
Finance leases
Property and equipment	$ 24,534		19,482
Accumulated depreciation	(13,186)		(8,728)
Property and equipment, net	11,348		10,754
Other current liabilities	14
Other liabilities	39
Total finance lease liabilities	53
Right-of-use assets under finance leases
Finance leases
Property and equipment	1,854		$ 1,839
Accumulated depreciation	(1,004)
Property and equipment, net	$ 850