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

6 Months Ended

Jun. 30, 2023

Notes Tables

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

	June 30, 2023
	Amortized		Gross Unrealized		Gross Unrealized		Fair
	Cost		Gains		Losses		Value
Student Loan Pools	$	55,012,254	$	24,574	$	1,152,504	$	53,884,324
Small Business Administration (“SBA”) Bonds		86,796,430		456,505		3,092,775		84,160,160
Tax Exempt Municipal Bonds		21,565,323		389,470		1,293,005		20,661,788
Taxable Municipal Bonds		64,709,727		—		12,620,947		52,088,780
Mortgage-Backed Securities ("MBS")		366,537,252		20,821		35,400,499		331,157,574
Total Available For Sale	$	594,620,986	$	891,370	$	53,559,730	$	541,952,626

	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 Available For Sale	$	604,157,308	$	1,031,139	$	55,040,163	$	550,148,284

Investments Classified by Contractual Maturity Date [Table Text Block]

	June 30, 2023
Investments AFS:	Amortized Cost		Fair Value
One Year or Less	$	15,149	$	15,048
After One – Five Years		4,941,009		4,923,354
After Five – Ten Years		74,445,408		70,014,896
More Than Ten Years		148,682,168		135,841,754
MBS AFS		366,537,252		331,157,574
Total AFS	$	594,620,986	$	541,952,626

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

	June 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	$	2,219,356	$	9,373	$	46,923,563	$	1,143,131	$	49,142,919	$	1,152,504
SBA Bonds		4,287,109		12,009		41,374,318		3,080,766		45,661,427		3,092,775
Tax Exempt Municipal Bonds		510,280		23,629		12,712,000		1,269,376		13,222,280		1,293,005
Taxable Municipal Bonds		—		—		52,088,780		12,620,947		52,088,780		12,620,947
MBS		38,697,258		1,140,729		290,776,832		34,259,770		329,474,090		35,400,499
	$	45,714,003	$	1,185,740	$	443,875,493	$	52,373,990	$	489,589,496	$	53,559,730

	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