Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Temporarily Impaired Securities, Fair Value and Unrealized losses) (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	$ 29,789,084	$ 201,667,439
12 Months or More, Fair Value	452,653,442	288,502,788
Total, Fair Value	482,442,526	490,170,227
Less than 12 Months, Unrealized Losses	924,917	15,806,689
12 Months or More, Unrealized Losses	46,848,716	39,233,474
Total, Unrealized Losses	47,773,633	55,040,163
Student Loan Pools
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	6,532,605	24,768,260
12 Months or More, Fair Value	44,272,894	30,684,124
Total, Fair Value	50,805,499	55,452,384
Less than 12 Months, Unrealized Losses	96,105	637,963
12 Months or More, Unrealized Losses	1,207,874	1,071,360
Total, Unrealized Losses	1,303,979	1,709,323
SBA Bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	3,627,220	8,403,975
12 Months or More, Fair Value	44,567,268	45,969,373
Total, Fair Value	48,194,488	54,373,348
Less than 12 Months, Unrealized Losses	18,733	120,766
12 Months or More, Unrealized Losses	2,812,310	3,126,157
Total, Unrealized Losses	2,831,043	3,246,923
Tax Exempt Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	519,710	8,050,944
12 Months or More, Fair Value	12,819,506	4,929,289
Total, Fair Value	13,339,216	12,980,233
Less than 12 Months, Unrealized Losses	9,017	718,645
12 Months or More, Unrealized Losses	1,215,659	913,174
Total, Unrealized Losses	1,224,676	1,631,819
Taxable Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	14,427,796
12 Months or More, Fair Value	52,935,070	36,341,943
Total, Fair Value	52,935,070	50,769,739
Less than 12 Months, Unrealized Losses	0	3,196,761
12 Months or More, Unrealized Losses	11,794,778	11,283,383
Total, Unrealized Losses	11,794,778	14,480,144
MBS
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	19,109,549	146,016,464
12 Months or More, Fair Value	298,058,704	170,578,059
Total, Fair Value	317,168,253	316,594,523
Less than 12 Months, Unrealized Losses	801,062	11,132,554
12 Months or More, Unrealized Losses	29,818,095	22,839,400
Total, Unrealized Losses	$ 30,619,157	$ 33,971,954