Note 10 - Stockholders Equity - Summary of Warrant Activity (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Mar. 31, 2017
Outstanding (in shares)	180,001
Outstanding, weighted average exercise price (in dollars per share)	$ 0.57
Outstanding, weighted average exercise price (in dollars per share)	$ 0.34	$ 0.57
Outstanding, weighted average remaining contractual life (Year)	4 years 219 days	1 year 186 days
Outstanding, aggregate intrinsic value
Issued (in shares)	1,612,902
Issued (in dollars per share)	$ 0.31
Issued, weighted average remaining contractual life (Year)	5 years
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited/Cancelled (in shares)
Exercisable (in shares)	1,792,903
Exercisable, weighted average exercise price (in dollars per share)	$ 0.34
Exercisable, weighted average remaining contractual life (Year)	4 years 219 days
Exercisable, aggregate intrinsic value
Forfeited/Cancelled, weighted average exercise price (in dollars per share)
Outstanding (in shares)	1,792,903	180,001