Note 10 - Stockholders' Equity - Reconciliation of Activity in Stockholders' Equity Accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Balance	$ 29,562
Net income (loss)	(577)	$ (188)
Balance	29,006
Common Stock [Member]
Balance	54	684
Net income (loss)	0	0
Stock-based compensation expense	0	0
Balance	54	684
Additional Paid-in Capital [Member]
Balance	30,450	29,738
Net income (loss)	0	0
Stock-based compensation expense	21	21
Balance	30,471	29,759
Retained Earnings [Member]
Balance	(942)	(3,702)
Net income (loss)	(577)	(188)
Stock-based compensation expense	0	0
Balance	$ (1,519)	$ (3,890)