Fair Value of Financial Instruments - Summary of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	$ 747,375,587	$ 798,246,109
Mortgage Revenue Bonds Held In Trust [Member]
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	714,524,298	750,934,848
Mortgage Revenue Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	20,431,600	42,574,996
Bond Purchase Commitment [Member]
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	145,323	964,404
Taxable Mortgage Revenue Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	9,535,962	3,428,443
Derivative Financial Instruments (Reported within Other Assets) [Member]
Schedule of Available-for-sale Securities [Line Items]
Assets at Fair Value	2,738,404	343,418
Fair Value Inputs Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	2,340,746
Fair Value Inputs Level 2 [Member] | Derivative Financial Instruments (Reported within Other Assets) [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	2,340,746
Fair Value, Inputs, Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	745,034,841	798,246,109	$ 773,607,185	$ 796,696,304
Fair Value, Inputs, Level 3 [Member] | Mortgage Revenue Bonds Held In Trust [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	714,524,298	750,934,848
Fair Value, Inputs, Level 3 [Member] | Mortgage Revenue Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	20,431,600	42,574,996
Fair Value, Inputs, Level 3 [Member] | Bond Purchase Commitment [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	145,323	964,404	310,909	431,879
Fair Value, Inputs, Level 3 [Member] | Taxable Mortgage Revenue Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	9,535,962	3,428,443	$ 1,443,988	$ 1,510,437
Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments (Reported within Other Assets) [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 397,658	$ 343,418