Note 15 - Earnings Per Common Share - Earnings Per Common Share (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Basic earnings per share (in shares)	10,672,314	10,873,817	10,981,623
Basic earnings per share (in dollars per share)	$ 3.23	$ 4.00	$ 2.74
Effect of dilutive securities - stock options (in shares)	2,299	3,414	4,167
Effect of dilutive securities - stock options (in dollars per share)	$ 0	$ 0	$ (0.01)
Diluted earnings per share (in shares)	10,674,613	10,877,231	10,985,790
Diluted earnings per share (in dollars per share)	$ 3.23	$ 4.00	$ 2.73