Note 11 - Earnings Per Common Share - Earnings Per Common Share (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic earnings per share (in shares)	10,833,875	10,966,645	10,907,721	10,983,729
Basic earnings per share (in dollars per share)	$ 0.94	$ 0.66	$ 2.96	$ 1.93
Effect of dilutive securities - stock options (in shares)	2,418	3,256	3,651	4,361
Effect of dilutive securities - stock options (in dollars per share)	$ 0	$ 0	$ (0.01)	$ 0
Diluted earnings per share (in shares)	10,836,293	10,969,901	10,911,372	10,988,090
Diluted earnings per share (in dollars per share)	$ 0.94	$ 0.66	$ 2.95	$ 1.93