Note 10 - Stockholders Equity - Summary of Warrant Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Outstanding, weighted average remaining contractual life (Year)		4 years 255 days
Outstanding, aggregate intrinsic value
Issued (in shares)		625,000
Issued, weighted average exercise price (in dollars per share)		$ 0.20
Issued, weighted average remaining contractual life (Year)		4 years 328 days
Issued, aggregate intrinsic value
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited/Cancelled (in shares)
Forfeited/Cancelled, weighted average exercise price (in dollars per share)
Forfeited/Cancelled (in dollars per share)
Outstanding, weighted average exercise price (in dollars per share)		$ 0.22
Outstanding (in shares)		655,000
Outstanding at December 31, 2019 (in dollars per share)		$ 0.22			$ 0.22
Outstanding at December 31, 2019
Warrants Issued in June 2016 [Member]
Outstanding (in shares)		30,000	1,642,903
Outstanding, weighted average exercise price (in dollars per share)		$ 0.70	$ 0.32
Outstanding, weighted average remaining contractual life (Year)			2 years 182 days	4 years 182 days
Outstanding, aggregate intrinsic value								$ 539
Issued (in shares)	30,000
Issued, weighted average exercise price (in dollars per share)
Issued, weighted average remaining contractual life (Year)
Issued, aggregate intrinsic value
Exercised (in shares)			(1,612,903)
Exercised, weighted average exercise price (in dollars per share)			$ 0.31
Forfeited/Cancelled (in shares)
Forfeited/Cancelled, weighted average exercise price (in dollars per share)
Forfeited/Cancelled (in dollars per share)
Outstanding, weighted average exercise price (in dollars per share)			$ 0.70	$ 0.32
Outstanding (in shares)			30,000	1,642,903
Outstanding at December 31, 2019 (in dollars per share)		$ 0.70	$ 0.70	$ 0.32		$ 0.70	$ 0.70	$ 0.32
Outstanding at December 31, 2019								$ 539
Exercisable (in shares)					655,000
Exercisable, weighted average exercise price (in dollars per share)					$ 0.22
Exercisable, weighted average remaining contractual life (Year)		4 years 255 days
Exercisable, aggregate intrinsic value