Note 3 - Earnings (Loss) Per Share - Computation of Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Basic EPS, Income (loss) numerator	$ (992,609)	$ 1,529,781	$ (2,259,134)	$ 2,123,264
Weighted Average Number of Shares Outstanding, Basic, Total	159,289,879	150,275,406	158,321,294	149,966,378
Basic EPS, Per-share amount (in dollars per share)	$ (0.01)	$ 0.01	$ (0.01)	$ 0.01
Effect of dilutive securities, Income (loss) numerator	$ 0	$ (281,506)	$ 0	$ (317,701)
Effect of dilutive securities, Shares denominator (in shares)	0	14,101,417	0	14,101,417
Effect of dilutive securities, Per-share amount (in dollars per share)	$ 0	$ (0.02)	$ 0	$ (0.02)
Diluted EPS, Income (loss) numerator	$ (992,609)	$ 1,248,275	$ (2,259,134)	$ 1,805,563
Diluted EPS, Shares denominator (in shares)	159,289,879	164,376,823	158,321,294	164,067,795
Diluted EPS, Per-share amount (in dollars per share)	$ (0.01)	$ 0.01	$ (0.01)	$ 0.01