Segments - Summary of Partnership Reportable Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Total revenues
Total revenues	$ 17,681,901	$ 13,839,947	$ 48,475,885	$ 42,054,501
Interest expense
Interest expense	5,663,452	5,105,432	16,248,023	16,012,716
Depreciation expense
Depreciation expense	680,925	719,783	2,049,269	2,141,302
Net income (loss)
Net income (loss)	12,988,384	(1,160,017)	30,245,918	6,410,088
Total assets
Total assets	1,284,501,519		1,284,501,519		$ 1,175,247,879
Operating Segments [Member] | Mortgage Revenue Bond Investments Segment [Member]
Total revenues
Total revenues	12,795,214	10,763,544	34,624,484	31,216,575
Interest expense
Interest expense	5,186,465	4,813,114	15,166,356	14,908,641
Depreciation expense
Depreciation expense	5,912	4,688	17,534	10,471
Net income (loss)
Net income (loss)	3,453,537	(1,852,974)	7,293,774	888,856
Total assets
Total assets	1,223,689,462		1,223,689,462		1,114,146,614
Operating Segments [Member] | MF Properties [Member]
Total revenues
Total revenues	1,811,778	1,548,931	5,294,475	5,358,132
Interest expense
Interest expense	283,111	292,318	847,292	906,082
Depreciation expense
Depreciation expense	675,013	715,095	2,031,735	2,130,831
Net income (loss)
Net income (loss)	(301,286)	(834,648)	(594,599)	(1,172,961)
Total assets
Total assets	67,379,270		67,379,270		67,988,190
Operating Segments [Member] | Public Housing Capital Fund Trusts [Member]
Total revenues
Total revenues				174,470
Interest expense
Interest expense				197,993
Net income (loss)
Net income (loss)				1,390,999
Operating Segments [Member] | Other Investments [Member]
Total revenues
Total revenues	3,074,909	1,527,472	8,556,926	5,305,324
Interest expense
Interest expense	193,876		234,375
Net income (loss)
Net income (loss)	9,836,133	$ 1,527,605	23,546,743	$ 5,303,194
Total assets
Total assets	92,248,043		92,248,043		106,931,182
Consolidation, Eliminations [Member]
Total assets
Total assets	$ (98,815,256)		$ (98,815,256)		$ (113,818,107)