Leases - Lease Cost and Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease cost
Operating lease cost	$ 1,578	$ 1,443
Variable lease cost	167	152
Total lease cost	$ 1,745	$ 1,595
Weighted average lease term	2 years 7 months 20 days
Weighted average discount rate	5.60%
Maturities of operating lease liabilities
2021	$ 2,419
2022	3,055
2023	2,065
Total future minimum lease payments	7,539
Less imputed interest	(554)
Present value of lease liabilities	$ 6,985