Note 9 - Summary of the Status of the Warrants Outstanding (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Exercise Price 1 [Member]
Warrants Outstanding and Exercisable Number Outstanding (in shares) | shares	3,283,283
Warrants Outstanding and Exercisable Weighted Average Remaining Contractual Life	5 years
Warrants Outstanding and Exercisable Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 0.25
Exercise Price 2 [Member]
Warrants Outstanding and Exercisable Number Outstanding (in shares) | shares	461,340
Warrants Outstanding and Exercisable Weighted Average Remaining Contractual Life	4 years 302 days
Warrants Outstanding and Exercisable Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.15
Exercise Price 3 [Member]
Warrants Outstanding and Exercisable Number Outstanding (in shares) | shares	54,367
Warrants Outstanding and Exercisable Weighted Average Remaining Contractual Life	32 days
Warrants Outstanding and Exercisable Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 2
Warrants Outstanding and Exercisable Number Outstanding (in shares) | shares	3,798,990
Warrants Outstanding and Exercisable Weighted Average Remaining Contractual Life	4 years 332 days
Warrants Outstanding and Exercisable Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 0.38