Note 2 - Restatement of Previously Issued Financial Statements - Restatement of Previously Issued Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Additional paid-in capital	$ 40,760		$ 30,052
Accumulated deficit	(30,006)		(27,529)
Other (expense) income	(78)	$ 20
Total other expense	(111)	(621)
Loss from continuing operations before taxes	(2,469)	(2,873)
Loss from continuing operations	(2,469)	(2,873)
Net loss	$ (2,477)	$ (2,837)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ (0.27)	$ (0.78)
Net loss per share - basic and diluted (in dollars per share)	$ (0.27)	$ (0.77)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	$ 1,553
Balance	10,811	$ (5,474)	2,555	$ (2,676)
OPERATING ACTIVITIES
Net loss	(2,477)	(2,837)
Loss from continuing operations	(2,469)	(2,873)
Fair value of warrant issued upon conversion of subordinated debt to equity	304
Additional Paid-in Capital [Member]
Net loss
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	1,550
Balance	40,760	22,364	30,052	22,325
OPERATING ACTIVITIES
Net loss
Retained Earnings [Member]
Net loss	(2,477)	(2,837)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount
Balance	(30,006)	(2,837)	$ (27,529)	$ (25,020)
OPERATING ACTIVITIES
Net loss	(2,477)	$ (2,837)
Previously Reported [Member]
Additional paid-in capital	40,456
Accumulated deficit	(29,702)
Other (expense) income	226
Total other expense	193
Loss from continuing operations before taxes	(2,165)
Loss from continuing operations	(2,165)
Net loss	$ (2,173)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ (0.24)
Net loss per share - basic and diluted (in dollars per share)	$ (0.24)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	$ 1,249
Balance	10,811
OPERATING ACTIVITIES
Net loss	(2,173)
Loss from continuing operations	(2,165)
Fair value of warrant issued upon conversion of subordinated debt to equity
Previously Reported [Member] | Additional Paid-in Capital [Member]
Net loss
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	1,246
Balance	40,456
OPERATING ACTIVITIES
Net loss
Previously Reported [Member] | Retained Earnings [Member]
Net loss	(2,173)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount
Balance	(29,702)
OPERATING ACTIVITIES
Net loss	(2,173)
Revision of Prior Period, Adjustment [Member]
Additional paid-in capital	304
Accumulated deficit	(304)
Other (expense) income	(304)
Total other expense	(304)
Loss from continuing operations before taxes	(304)
Loss from continuing operations	(304)
Net loss	$ (304)
Loss from continuing operations per common share - basic and diluted (in dollars per share)	$ (0.03)
Net loss per share - basic and diluted (in dollars per share)	$ (0.03)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	$ 304
Balance
OPERATING ACTIVITIES
Net loss	(304)
Loss from continuing operations	(304)
Fair value of warrant issued upon conversion of subordinated debt to equity	304
Revision of Prior Period, Adjustment [Member] | Additional Paid-in Capital [Member]
Net loss
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount	304
Balance	304
OPERATING ACTIVITIES
Net loss
Revision of Prior Period, Adjustment [Member] | Retained Earnings [Member]
Net loss	(304)
Shares and warrant issued to Cross River Partners, L.P. in subordinated debt and accrued interest conversion, net of discount
Balance	(304)
OPERATING ACTIVITIES
Net loss	$ (304)