Note 5 - Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating lease right-of-use assets, net	$ 727	$ 429
Current lease liabilities	579	432
Non-current office leases	169	0
Total lease liabilities	748	432
Office Leases [Member]
Operating lease right-of-use assets, net	727	429
Current lease liabilities	$ 579	$ 432