Note 1 - Summary of Significant Accounting Policies - Other Comprehensive Earnings (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Unrealized holding losses arising during the period, pre tax	$ (4,315,110)	$ (748,597)	$ (15,659,030)	$ (2,188,767)
Unrealized holding losses arising during the period, tax	906,173	157,205	(3,288,396)	(459,641)
Unrealized holding losses arising during the period, after tax	(3,408,937)	(591,392)	(12,370,634)	(1,729,126)
Reclassification adjustment for losses (gains) included in net earnings, pre-tax	0	(113,397)	628	(123,271)
Reclassification adjustment for losses (gains) included in net earnings, tax	0	23,814	132	(25,887)
Reclassification adjustment for losses (gains) included in net earnings, after-tax	0	(89,583)	496	(97,384)
Total other comprehensive loss, pre tax	(4,315,110)	(861,994)	(15,658,402)	(2,312,038)
Total other comprehensive loss, tax	906,173	181,019	(3,288,264)	(485,528)
Total other comprehensive loss, after tax	(3,408,937)	(680,975)	(12,370,138)	(1,826,510)
Unrealized holding losses arising during the period, tax	(906,173)	(157,205)	3,288,396	459,641
Reclassification adjustment for losses (gains) included in net earnings, pre-tax	0	113,397	(628)	123,271
Reclassification adjustment for losses (gains) included in net earnings, tax	0	(23,814)	(132)	25,887
Total other comprehensive loss, tax	$ (906,173)	$ (181,019)	$ 3,288,264	$ 485,528