Note 10 - Stock Options - Summary of the Status of Non-vested Shares (Details) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Balance, non-vested (in shares)	1,323,669
Balance, non-vested (in dollars per share)	$ 1.22
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	3,525,000	1,123,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0.28	$ 1.19
Vested (in shares)	(1,401,333)
Vested (in dollars per share)	$ 0.55
Forfeited or Expired (in shares)	(1,179,500)
Forfeited or Expired (in dollars per share)	$ 0.53
Balance, non-vested (in shares)	2,267,836
Balance, non-vested (in dollars per share)	$ 0.53