Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Lease expense
Operating lease	$ 133	$ 127	$ 266	$ 255
Short-term lease expense	28	21	52	34
Total	$ 161	$ 148	$ 318	$ 289