Note 11 - Stockholders' Equity - Reconciliation of Activity in Stockholders' Equity Accounts (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance			$ 26,720				$ 26,720
Net income (loss)	$ 3,281			$ (446)			2,984	$ 432
Balance	29,766						29,766
Common Stock [Member]
Balance	684	$ 684	684	684	$ 294	$ 294	684	294
Net income (loss)	0	0	0	0	0	0
Stock-based compensation expense	0	0	0	0	0	0
Effect of reverse stock split	(630)
Redemption of fractional shares	0
Issuance of common stock					390
Balance	54	684	684	684	684	294	54	684
Additional Paid-in Capital [Member]
Balance	29,780	29,759	29,738	29,696	17,391	17,370	29,738	17,370
Net income (loss)	0	0	0	0	0	0
Stock-based compensation expense	22	21	21	21	20	21
Effect of reverse stock split	630
Redemption of fractional shares	(2)
Issuance of common stock					12,285
Balance	30,430	29,780	29,759	29,717	29,696	17,391	30,430	29,717
Retained Earnings [Member]
Balance	(3,999)	(3,890)	(3,702)	(2,886)	(2,711)	(3,765)	(3,702)	(3,765)
Net income (loss)	3,281	(109)	(188)	(446)	(175)	1,054
Stock-based compensation expense	0	0	0	0	0	0
Effect of reverse stock split	0
Redemption of fractional shares	0
Issuance of common stock					0
Balance	$ (718)	$ (3,999)	$ (3,890)	$ (3,332)	$ (2,886)	$ (2,711)	$ (718)	$ (3,332)