Note 5 - Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating lease costs	$ 839	$ 612
Short-term lease costs	277	51
Total operating lease costs	1,116	663
Variable lease costs	357	299
Total lease expense	$ 1,473	$ 962