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Fair Value of Financial Instruments - Summary of Activity Related to Level 3 Assets and Liabilities (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Schedule of Available-for-sale Securities [Line Items] |  |  |  |
Assets at Fair Value, beginning balance | $ 1,056,980,128 | $ 953,861,216 | $ 1,053,154,881 | $ 952,333,636
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) | (273,819) | 53,529 | (255,072) | 118,631
Total gain (losses) Included in earnings (provision for credit losses) | $ (8,707,000) | 169,308 | $ (8,707,000) | 169,308
Total gain (losses) Included in earnings(gain on sale of mortgag revenue bond) |  | $ 1,012,581 |  | $ 1,012,581
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Interest Income (Expense), Operating | Interest Income (Expense), Operating | Interest Income (Expense), Operating | Interest Income (Expense), Operating
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax | OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax | OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax | OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax
Total gain (losses) included in other comprehensive (loss) income | $ (807,707) | $ (10,696,569) | $ (6,442,766) | $ (22,768,265)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances | 23,511,764 | 83,452,062 | 45,012,807 | 110,749,860
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales |  | (8,221,234) |  | (8,221,234)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions | (29,664,371) | (1,606,309) | (41,723,855) | (15,369,933)
Assets at Fair Value, ending balance | 1,041,038,995 | 1,018,024,584 | 1,041,038,995 | 1,018,024,584
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets or liabilities held | (8,786,191) | 186,619 | (8,769,224) | 203,543
Derivative Instruments [Member] |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |
Derivative Assets (Liabilities) at Fair Value, beginning balance |  | 34 |  | 265
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) |  | (34) |  | (265)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements and redemptions |  | 0 |  | 0
Derivative Assets (Liabilities) at Fair Value, ending balance |  | 0 |  | 0
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets or liabilities held |  | (34) |  | (265)
Bond Purchase Commitment [Member] |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |
Assets at Fair Value, beginning balance |  | 134,829 |  | 197,788
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |
Total gain (losses) included in other comprehensive (loss) income | 1,833,078 | (88,591) | 1,833,078 | (151,550)
Assets at Fair Value, ending balance | 1,833,078 | 46,238 | 1,833,078 | 46,238
Taxable Mortgage Revenue Bonds [Member] |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |
Assets at Fair Value, beginning balance | 34,416,164 | 10,980,756 | 26,671,085 | 21,460,288
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) | (1,738) | (2,894) | (5,050) | (8,944)
Total gain (losses) Included in earnings (provision for credit losses) | (267,100) |  | (267,100) |
Total gain (losses) included in other comprehensive (loss) income | 13,553 | (125,411) | 500,291 | (95,834)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances | 800,000 | 5,077,000 | 8,200,000 | 6,077,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions | (218,422) | (3,130) | (356,769) | (11,506,189)
Assets at Fair Value, ending balance | 34,742,457 | 15,926,321 | 34,742,457 | 15,926,321
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets or liabilities held | (267,100) |  | (267,100) |
Mortgage Revenue Bonds [Member] |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |
Assets at Fair Value, beginning balance | 1,022,563,964 | 942,745,597 | 1,026,483,796 | 930,675,295
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) | (272,081) | 56,457 | (250,022) | 127,840
Total gain (losses) Included in earnings (provision for credit losses) | (8,439,900) | 169,308 | (8,439,900) | 169,308
Total gain (losses) Included in earnings(gain on sale of mortgag revenue bond) |  | 1,012,581 |  | 1,012,581
Total gain (losses) included in other comprehensive (loss) income | (2,654,338) | (10,482,567) | (8,776,135) | (22,520,881)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances | 22,711,764 | 78,375,062 | 36,812,807 | 104,672,860
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales |  | (8,221,234) |  | (8,221,234)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions | (29,445,949) | (1,603,179) | (41,367,086) | (3,863,744)
Assets at Fair Value, ending balance | 1,004,463,460 | 1,002,052,025 | 1,004,463,460 | 1,002,052,025
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets or liabilities held | $ (8,519,091) | $ 186,653 | $ (8,502,124) | $ 203,808

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