Note 6 - Investments, Available for Sale ("AFS") (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]

	September 30, 2023
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Student Loan Pools	$	53,149,118	$	93,233	$	(748,230	)	$	52,494,121
Small Business Administration (“SBA”) Bonds		80,809,436		408,529		(3,291,469	)		77,926,496
Tax Exempt Municipal Bonds		21,486,631		108,726		(2,123,259	)		19,472,098
Taxable Municipal Bonds		64,689,585		—		(15,278,275	)		49,411,310
Mortgage-Backed Securities ("MBS")		371,796,460		3,408		(39,682,320	)		332,117,548
Total Investments AFS	$	591,931,230	$	613,896	$	(61,123,553	)	$	531,421,573

	December 31, 2022
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Student Loan Pools	$	60,854,658	$	11,647	$	(1,709,323	)	$	59,156,982
SBA Bonds		102,292,600		584,290		(3,246,923	)		99,629,967
Tax Exempt Municipal Bonds		22,536,806		405,341		(1,631,819	)		21,310,328
Taxable Municipal Bonds		65,249,883		—		(14,480,144	)		50,769,739
MBS		353,223,361		29,861		(33,971,954	)		319,281,268
Total Investments AFS	$	604,157,308	$	1,031,139	$	(55,040,163	)	$	550,148,284

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30, 2023
Investments AFS:	Amortized Cost		Fair Value
One Year or Less	$	13,693	$	13,525
After One – Five Years		6,593,553		6,546,193
After Five – Ten Years		76,090,051		69,654,980
More Than Ten Years		137,437,473		123,089,327
MBS AFS		371,796,460		332,117,548
Total AFS	$	591,931,230	$	531,421,573

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]

	September 30, 2023
	Less than 12 Months					12 Months or More					Total
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Student Loan Pools	$	411,097	$	(964	)	$	45,703,435	$	(747,266	)	$	46,114,532	$	(748,230	)
SBA Bonds		3,492,535		(8,044	)		39,107,655		(3,283,425	)		42,600,190		(3,291,469	)
Tax Exempt Municipal Bonds		3,648,687		(71,499	)		12,414,886		(2,051,760	)		16,063,573		(2,123,259	)
Taxable Municipal Bonds		—		—			49,411,310		(15,278,275	)		49,411,310		(15,278,275	)
MBS		36,969,372		(439,141	)		289,240,242		(39,243,179	)		326,209,614		(39,682,320	)
	$	44,521,691	$	(519,648	)	$	435,877,528	$	(60,603,905	)	$	480,399,219	$	(61,123,553	)

	December 31, 2022
	Less than 12 Months					12 Months or More					Total
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Student Loan Pools	$	24,768,260	$	(637,963	)	$	30,684,124	$	(1,071,360	)	$	55,452,384	$	(1,709,323	)
SBA Bonds		8,403,975		(120,766	)		45,969,373		(3,126,157	)		54,373,348		(3,246,923	)
Tax Exempt Municipal Bonds		8,050,944		(718,645	)		4,929,289		(913,174	)		12,980,233		(1,631,819	)
Taxable Municipal Bonds		14,427,796		(3,196,761	)		36,341,943		(11,283,383	)		50,769,739		(14,480,144	)
MBS		146,016,464		(11,132,554	)		170,578,059		(22,839,400	)		316,594,523		(33,971,954	)
	$	201,667,439	$	(15,806,689	)	$	288,502,788	$	(39,233,474	)	$	490,170,227	$	(55,040,163	)