Note 10 - Stockholders Equity - Summary of Warrant Activity (Details) - Warrant [Member] - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Outstanding (in shares)		180,001	1,642,903	180,001
Outstanding, weighted average exercise price (in dollars per share)		$ 0.57	$ 0.32	$ 0.57
Outstanding, weighted average remaining contractual life (Year)	4 years 182 days	1 year 182 days	2 years 182 days
Outstanding, aggregate intrinsic value		$ 2				$ 539
Issued (in shares)				1,612,902
Issued, weighted average exercise price (in dollars per share)				$ 0.31
Issued, weighted average remaining contractual life (Year)				4 years 182 days
Issued, aggregate intrinsic value						$ 539
Cashless exercise of warrants, net of issuance costs (in shares)			(1,612,902)	(112,500)
Exercised, weighted average exercise price (in dollars per share)			$ 0.31	$ 0.55
Forfeited/Cancelled (in shares)				(37,500)
Forfeited/Cancelled, weighted average exercise price (in dollars per share)
Outstanding, weighted average exercise price (in dollars per share)	$ 0.32		$ 0.70	$ 0.32
Outstanding (in shares)	1,642,903		30,000	1,642,903
Outstanding, weighted average exercise price (in dollars per share)	$ 0.32	$ 0.57	$ 0.32	$ 0.57	$ 0.70	$ 0.32
Exercisable (in shares)					30,000
Exercisable, weighted average exercise price (in dollars per share)					$ 0.70
Exercisable, weighted average remaining contractual life (Year)			2 years 182 days