Leases - Lease Cost and Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lease cost
Operating lease cost	$ 1,443
Variable lease cost	$ 152
Weighted average lease term	1 year 5 months 19 days
Discount rate	7.16%
Maturities of operating lease liabilities
2020	$ 1,821
2021	972
Total future minimum lease payments	2,793
Less imputed interest	(141)
Present value of lease liabilities	$ 2,652
Future minimum lease payments
2019		$ 1,394
2020		1,821
2021		972
Total future minimum lease payments		$ 4,187