Leases - Lease Cost and Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lease cost
Operating lease cost	$ 341	$ 361	$ 681	$ 762
Variable lease cost	52	87	102	109
Total lease cost	$ 393	$ 448	$ 783	$ 871
Weighted average lease term	11 months 23 days		11 months 23 days
Weighted average discount rate	7.16%		7.16%
Maturities of operating lease liabilities
2020	$ 911		$ 911
2021	972		972
Total future minimum lease payments	1,883		1,883
Less imputed interest	(64)		(64)
Present value of lease liabilities	$ 1,819		$ 1,819