Note 5 - Operating Lease Right-of-use Asset, Net - Supplement Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities	$ 686	$ 630
Cash lease expense (imputed interest expense component of net income)	(43)	(103)
Total rent expense	$ 729	$ 733