Segments - Summary of Partnership Reportable Segment Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Total revenues
Total revenues	$ 16,406,496	$ 14,478,419	$ 30,793,984	$ 28,214,554
Interest expense
Interest expense	5,358,096	4,889,316	10,584,571	10,907,284
Depreciation expense
Depreciation expense	684,884	712,081	1,368,344	1,421,519
Net income (loss)
Net income (loss)	10,264,680	4,588,348	17,257,534	7,570,105
Total assets
Total assets	1,233,985,859		1,233,985,859		$ 1,175,247,879
Operating Segments [Member] | Mortgage Revenue Bond Investments Segment [Member]
Total revenues
Total revenues	11,034,482	10,247,228	21,829,270	20,453,031
Interest expense
Interest expense	5,035,615	4,597,328	9,979,892	10,095,527
Depreciation expense
Depreciation expense	5,811	3,359	11,622	5,783
Net income (loss)
Net income (loss)	1,290,784	2,301,494	3,840,236	2,741,830
Total assets
Total assets	1,172,640,853		1,172,640,853		1,114,146,614
Operating Segments [Member] | MF Properties [Member]
Total revenues
Total revenues	1,788,173	1,856,954	3,482,697	3,809,201
Interest expense
Interest expense	281,983	291,988	564,181	613,764
Depreciation expense
Depreciation expense	679,073	708,722	1,356,722	1,415,736
Net income (loss)
Net income (loss)	(30,494)	(85,583)	(293,313)	(338,313)
Total assets
Total assets	67,387,271		67,387,271		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	3,583,841	2,374,237	5,482,017	3,777,852
Interest expense
Interest expense	40,498		40,498
Net income (loss)
Net income (loss)	9,004,390	$ 2,372,437	13,710,611	$ 3,775,589
Total assets
Total assets	96,636,495		96,636,495		106,931,182
Consolidation, Eliminations [Member]
Total assets
Total assets	$ (102,678,760)		$ (102,678,760)		$ (113,818,107)