Note 5 - Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Operating lease right-of-use assets, net	$ 860	$ 429
Current lease liabilities	504	432
Non-current office leases	333	0
Total lease liabilities	837	432
Office Leases [Member]
Operating lease right-of-use assets, net	860	429
Current lease liabilities	$ 504	$ 432