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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, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Assets at Fair Value, beginning balance |  | $ 953,861,216 | $ 886,026,783 | $ 952,333,636 | $ 816,370,069
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) |  | 53,529 | $ 1,383,541 | 118,631 | $ 2,772,369
Total gain (losses) Included in earnings (impairment of securities and provision for credit loss) |  | 169,308 |  | 169,308 |
Total gain (losses) Included in earnings (gain on sale of securities) |  | $ 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, Net Derivative Asset (Liability), 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 |  | $ (10,696,569) | $ (11,572,946) | $ (22,768,265) | $ 8,937,143
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances |  | 83,452,062 | 55,679,750 | 110,749,860 | 118,107,563
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 |  | (1,606,309) | (2,816,007) | (15,369,933) | (17,486,023)
Assets at Fair Value, ending balance |  | 1,018,024,584 | 928,701,121 | 1,018,024,584 | 928,701,121
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets or liabilities held |  | 186,619 | 9,110 | 203,543 | 20,053
Interest Rate Derivative Instruments [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Derivative Assets (Liabilities) at Fair Value, beginning balance |  | 34 | 285,145 | 265 | 331,240
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) |  | (34) | 1,311,754 | (265) | 2,629,139
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions |  |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements and redemptions |  |  | (1,295,275) |  | (2,658,755)
Derivative Assets (Liabilities) at Fair Value, ending balance |  | 0 | 301,624 | 0 | 301,624
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets or liabilities held |  | (34) | (8,235) | (265) | (14,259)
Bond Purchase Commitment [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Assets at Fair Value, beginning balance |  | 134,829 | 211,476 | 197,788 | 98,929
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |  |
Total gain (losses) included in other comprehensive (loss) income |  | (88,591) | (73,376) | (151,550) | 39,171
Assets at Fair Value, ending balance |  | 46,238 | 138,100 | 46,238 | 138,100
Taxable Mortgage Revenue Bonds [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Assets at Fair Value, beginning balance |  | 10,980,756 | 18,146,540 | 21,460,288 | 16,531,896
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) |  | (2,894) | (6,049) | (8,944) | (12,099)
Total gain (losses) included in other comprehensive (loss) income |  | (125,411) | (355,087) | (95,834) | (536,596)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances |  | 5,077,000 | 4,514,875 | 6,077,000 | 6,319,875
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions |  | (3,130) | (2,861) | (11,506,189) | (5,658)
Assets at Fair Value, ending balance |  | 15,926,321 | 22,297,418 | 15,926,321 | 22,297,418
Mortgage Revenue Bonds [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Assets at Fair Value, beginning balance | [1] | 942,745,597 | 867,383,622 | 930,675,295 | 799,408,004
Total gains (losses) (realized/unrealized) [Abstract] |  |  |  |  |
Total gain (losses) included in earnings (interest income and interest expense) | [1] | 56,457 | 77,836 | 127,840 | 155,329
Total gain (losses) Included in earnings (impairment of securities and provision for credit loss) | [1] | 169,308 |  | 169,308 |
Total gain (losses) Included in earnings (gain on sale of securities) | [1] | 1,012,581 |  | 1,012,581 |
Total gain (losses) included in other comprehensive (loss) income | [1] | (10,482,567) | (11,144,483) | (22,520,881) | 9,434,568
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and advances | [1] | 78,375,062 | 51,164,875 | 104,672,860 | 111,787,688
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales | [1] | (8,221,234) |  | (8,221,234) |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements and redemptions | [1] | (1,603,179) | (1,517,871) | (3,863,744) | (14,821,610)
Assets at Fair Value, ending balance | [1] | 1,002,052,025 | 905,963,979 | 1,002,052,025 | 905,963,979
Total amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets or liabilities held | [1] | $ 186,653 | $ 17,345 | $ 203,808 | $ 34,312
[1] | Mortgage revenue bonds includes both bonds held in trust as well as those held by the Partnership.

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- Definition Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 101 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-101 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 102 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-102 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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