Note 6 - Indebtedness - Changes in Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Proceeds from the sale of convertible promissory notes and warrants, net of debt issuance costs of $7 and $5 respectively	$ 810	$ 1,329
Convertible Debt [Member]
Balances at January 1, 2019	1,359
Accrued interest at January 1, 2019	2
Proceeds from the sale of convertible promissory notes and warrants, net of debt issuance costs of $7 and $5 respectively	816
Accrued Interest	103
Aggregate principal value of notes converted into common stock	(2,175)
Accrued interest converted into common stock and warrants	(105)
Balances at December 31, 2019		1,359
Accrued interest at December 31, 2019		$ 2