Note 2 - Restatement of Previously Issued Financial Statements - Effects of Restatements on Financial Statement (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Deferred tax liability, net	$ 948				$ 948		$ 0
Total long-term liabilities	18,153				18,153		23,054
Total liabilities	22,370				22,370		27,628
Accumulated deficit	(32,864)				(32,864)		(27,529)
Total stockholders' equity	7,978	$ 9,386	$ (9,504)	$ (5,474)	7,978	$ (9,504)	2,555	$ (2,676)
Deferred income tax benefit	477		(9)		(948)	(9)
Loss from continuing operations	(1,433)		(4,388)		(5,327)	(7,261)
Net loss	$ (1,433)	(3,902)	$ (4,357)	(2,837)	$ (5,335)	$ (7,194)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ (0.13)		$ (1.19)		$ (0.52)	$ (1.96)
Net loss per share - basic and diluted (in dollars per share)	$ (0.13)		$ (1.18)		$ (0.52)	$ (1.95)
Deferred income tax expense	$ (477)		$ 9		$ 948	$ 9
Retained Earnings [Member]
Total stockholders' equity	(32,864)	(31,431)	(32,214)	(27,857)	(32,864)	(32,214)	(27,529)	(25,020)
Net loss	(1,433)	(3,902)	(4,357)	(2,837)
Additional Paid-in Capital [Member]
Total stockholders' equity	40,785	40,760	22,691	22,364	40,785	$ 22,691	$ 30,052	$ 22,325
Net loss	0	0		$ 0
Previously Reported [Member]
Deferred tax liability, net	0				0
Total long-term liabilities	17,205				17,205
Total liabilities	21,422				21,422
Accumulated deficit	(31,916)				(31,916)
Total stockholders' equity	8,926	10,811			8,926
Deferred income tax benefit
Loss from continuing operations	(1,910)				(4,379)
Net loss	$ (1,910)	(2,477)			$ (4,387)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ (0.17)				$ (0.43)
Net loss per share - basic and diluted (in dollars per share)	$ (0.17)				$ (0.43)
Deferred income tax expense
Previously Reported [Member] | Retained Earnings [Member]
Total stockholders' equity	(31,916)	(30,006)			(31,916)
Net loss	(1,910)	(2,477)
Previously Reported [Member] | Additional Paid-in Capital [Member]
Total stockholders' equity	40,785	40,760			40,785
Revision of Prior Period, Adjustment [Member]
Deferred tax liability, net	948				948
Total long-term liabilities	948				948
Total liabilities	948				948
Accumulated deficit	(948)				(948)
Total stockholders' equity	(948)				(948)
Deferred income tax benefit	477				(948)
Loss from continuing operations	477				(948)
Net loss	$ 477				$ (948)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ 0.04				$ (0.09)
Net loss per share - basic and diluted (in dollars per share)	$ 0.04				$ (0.09)
Deferred income tax expense	$ (477)				$ 948
Revision of Prior Period, Error Correction, Adjustment [Member]
Total stockholders' equity	477	(1,425)			477
Net loss	477	(1,425)
Revision of Prior Period, Error Correction, Adjustment [Member] | Retained Earnings [Member]
Total stockholders' equity	477	(1,425)			$ 477
Net loss	$ 477	$ (1,425)