Note 13 - Stock Option Activity (Details)	12 Months Ended		154 Months Ended
	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 $ / shares shares	Dec. 31, 2015 $ / shares shares
Minimum [Member]
Outstanding (in dollars per share)	$ 0.69	$ 0.69	$ 0.69
Outstanding (in dollars per share)	0.69	0.69	0.69
Maximum [Member]
Outstanding (in dollars per share)	3.84	3.84	3.84
Outstanding (in dollars per share)	$ 3.84	$ 3.84	$ 3.84
Options outstanding at January 1 (in shares) | shares	274,500	270,500
Options cancelled (in shares) | shares	(8,000)	(12,000)
Options exercised (in shares) | shares	(4,000)		(728,320)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares	12,000	16,000	1,243,500
Options outstanding at December 31 (in shares) | shares	274,500	274,500	274,500
Options available for grant at December 31 (in shares) | shares	876,000	138,000	876,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | shares	254,500	250,000	254,500
Granted (in dollars per share)	$ 2.97	$ 1.35
Exercised (in dollars per share)	2.08
Outstanding at December 31 (in dollars per share)	1.76	1.72	$ 1.76
Exercisable at December 31 (in dollars per share)	$ 1.72	$ 1.76	$ 1.72