Note 2 - Earnings Per Share - Weighted Average Shares Used in Basic and Dilutive Earnings Per Share Computations (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Income	$ 1,008,000	$ 802,000	$ 2,171,000	$ 1,880,000
Weighted average shares outstanding – basic (in shares)	1,982,697	1,966,003	1,975,111	1,953,367
Effect of dilutive common stock equivalents (in shares)	28,118	45,572	35,537	46,427
Adjusted weighted average shares outstanding – diluted (in shares)	2,010,815	2,011,575	2,010,648	1,999,794
Basic earnings per share (in dollars per share)	$ 0.51	$ 0.41	$ 1.10	$ 0.96
Diluted earnings per share (in dollars per share)	$ 0.50	$ 0.40	$ 1.08	$ 0.94