Note 1 - Organization and Significant Accounting Policies - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net income (loss)	$ 80,000	$ (30,364)	$ 19,546	$ (210,097)
Basic weighted-average shares outstanding (in shares)	7,775,266	7,759,142	7,774,270	7,110,755
Effect of dilutive securities (in shares)	25,996	0	29,874	0
Diluted weighted-average shares outstanding (in shares)	7,801,262	7,759,142	7,804,144	7,110,755
Basic income (loss) per share (in dollars per share)	$ 0.01	$ 0	$ 0	$ (0.03)
Diluted income (loss) per share (in dollars per share)	$ 0.01	$ 0	$ 0	$ (0.03)