Note 11 - Stock Options - Summary of Stock Option Activity (Details) - USD ($)		6 Months Ended
	Dec. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Outstanding (in shares)		4,211,168
Outstanding, weighted average exercise price (in dollars per share)		$ 1.09
Outstanding, weighted average exercise price (in dollars per share)	$ 1.09	$ 0.78
Outstanding, weighted average remaining contractual life (Year)	2 years 310 days	2 years 295 days
Outstanding, aggregate intrinsic value	$ 46,233	$ 24,000
Granted (in shares)		2,171,600	1,565,000
Granted, weighted average exercise price (in dollars per share)		$ 0.31
Granted, weighted average remaining contractual life (Year)		4 years 339 days
Granted		$ 24,000
Exercised (in shares)		0
Exercised, weighted average exercise price (in dollars per share)
Forfeited or Expired (in shares)		(533,335)
Forfeited or Expired, weighted average exercise price (in dollars per share)		$ 1.38
Forfeited or Expired (Year)		1 year 200 days
Vested or Expected to Vest (in shares)		3,732,666
Vested or Expected to Vest, weighted average exercise price (in dollars per share)		$ 0.99
Vested or Expected to Vest, weighted average remaining contractual life (Year)		1 year 299 days
Vested or Expected to Vest, aggregate intrinsic value		$ 8,333
Exercisable (in shares)		3,732,666
Exercisable, weighted average exercise price (in dollars per share)		$ 0.99
Outstanding (in shares)	4,211,168	5,849,433
Exercisable, weighted average remaining contractual life (Year)		1 year 299 days
Exercisable, aggregate intrinsic value		$ 8,333