Right-of-use Asset and Lease Liability - Operating lease information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Right-of-use Asset and Lease Liability
Cash paid for operating lease liabilities	$ 159	$ 120
Right-of-use assets obtained in exchange for new operating lease obligations	$ 38
Weighted-average remaining lease term	5 years 9 months 18 days	6 years 10 months 24 days
Weighted-average discount rate	3.50%	3.40%