Right-of-use Asset and Lease Liability - Operating lease information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Right-of-use Asset and Lease Liability
Cash paid for operating lease liabilities	$ 248	$ 248
Right-of-use assets obtained in exchange for new operating lease obligations	$ 128	$ 2,163
Weighted-average remaining lease term	6 years 6 months	7 years 7 months 6 days
Weighted-average discount rate	3.30%	3.40%