Note 9 - Earnings (Loss) Per Share - Reconciliation of the Amounts Used in Calculating Basic and Diluted Net Loss per Common Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income (loss) available to common shareholders	$ 43,157	$ (34,620)	$ 313,972	$ (160,959)
Income (loss) available to common shareholders, shares (in shares)	11,980,397	11,211,760	11,633,464	11,211,760
Effect of dilutive stock options, shares (in shares)	684,870	0	671,718	0
Diluted net income (loss) per common share	$ 43,157	$ (34,620)	$ 313,972	$ (160,959)
Diluted net income per common share (in shares)	12,665,267	11,211,760	12,305,182	11,211,760
Income (loss) available to common shareholders	$ 43,157	$ (34,620)	$ 313,972	$ (160,959)
Diluted net income (loss) per common share	$ 43,157	$ (34,620)	$ 313,972	$ (160,959)
Income (loss) available to common shareholders, per share amount (in dollars per share)	$ 0	$ 0	$ 0.03	$ (0.01)
Diluted (in shares)	12,665,267	11,211,760	12,305,182	11,211,760
Net income (loss) per common share - diluted (in dollars per share)	$ 0	$ 0	$ 0.03	$ (0.01)
Basic (in shares)	11,980,397	11,211,760	11,633,464	11,211,760
Net income (loss) per common share - basic (in dollars per share)	$ 0	$ 0	$ 0.03	$ (0.01)