Segments - Summary of Partnership Reportable Segment Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Total revenues
Total revenues	$ 14,478,419	$ 14,346,334	$ 28,214,554	$ 32,010,932
Interest expense
Interest expense	4,889,316	6,206,935	10,907,284	12,601,855
Depreciation expense
Depreciation expense	712,081	818,154	1,421,519	1,637,312
Net income (loss)
Net income	4,588,348	3,886,190	7,570,105	10,338,003
Total assets
Total assets	1,038,489,468		1,038,489,468		$ 1,029,168,508
Operating Segments [Member] | Mortgage Revenue Bond Investments Segment [Member]
Total revenues
Total revenues	10,247,228	10,247,302	20,453,031	20,690,715
Interest expense
Interest expense	4,597,328	5,456,801	10,095,527	11,105,369
Depreciation expense
Depreciation expense	3,359		5,783
Net income (loss)
Net income	2,301,494	2,285,485	2,741,830	4,328,839
Total assets
Total assets	973,941,784		973,941,784		918,301,172
Operating Segments [Member] | MF Properties [Member]
Total revenues
Total revenues	1,856,954	2,034,796	3,809,201	4,028,425
Interest expense
Interest expense	291,988	365,632	613,764	730,021
Depreciation expense
Depreciation expense	708,722	818,154	1,415,736	1,637,312
Net income (loss)
Net income	(85,583)	(74,997)	(338,313)	(512,131)
Total assets
Total assets	69,044,411		69,044,411		70,569,646
Operating Segments [Member] | Public Housing Capital Fund Trusts [Member]
Total revenues
Total revenues		585,609	174,470	1,223,755
Interest expense
Interest expense		384,502	197,993	766,465
Net income (loss)
Net income		201,107	1,390,999	457,290
Total assets
Total assets					43,591,048
Operating Segments [Member] | Other Investments [Member]
Total revenues
Total revenues	2,374,237	1,478,627	3,777,852	6,068,037
Net income (loss)
Net income	2,372,437	$ 1,474,595	3,775,589	$ 6,064,005
Total assets
Total assets	91,683,948		91,683,948		87,098,315
Consolidation, Eliminations [Member]
Total assets
Total assets	$ (96,180,675)		$ (96,180,675)		$ (90,391,673)