Note 8 - Commitments and Contingencies - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating lease cost	$ 116	$ 116
Short-term lease cost	0	17
Variable lease cost	29	29
Total	145	162
Operating cash flows from operating leases	$ 138	$ 134