Segments - Summary of Partnership Reportable Segment Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Total revenues
Total revenues	$ 15,785,165	$ 16,234,300	$ 32,243,199	$ 32,274,688
Interest expense
Interest expense	5,918,867	5,841,327	10,801,172	11,283,580
Depreciation expense
Depreciation expense	919,456	1,265,335	1,823,409	2,620,566
Partnership net income (loss)
Partnership net income (loss)	3,338,121	4,109,400	9,342,425	11,398,262
Total assets
Total assets	1,023,530,880		1,023,530,880		$ 1,069,767,999
Operating Segments [Member] | Mortgage Revenue Bond Investments Segment [Member]
Total revenues
Total revenues	11,098,140	11,059,940	23,168,696	21,648,438
Interest expense
Interest expense	5,265,140	4,938,029	9,782,760	9,509,484
Partnership net income (loss)
Partnership net income (loss)	2,308,290	2,592,768	6,607,885	4,821,821
Total assets
Total assets	892,881,652		892,881,652		937,565,390
Operating Segments [Member] | MF Properties [Member]
Total revenues
Total revenues	2,477,442	3,306,722	4,813,954	7,099,137
Interest expense
Interest expense	408,131	534,245	798,832	1,059,832
Depreciation expense
Depreciation expense	919,456	1,265,335	1,823,409	2,620,566
Partnership net income (loss)
Partnership net income (loss)	(95,425)	18,047	(458,155)	3,763,592
Total assets
Total assets	82,642,061		82,642,061		83,514,758
Operating Segments [Member] | Public Housing Capital Fund Trusts [Member]
Total revenues
Total revenues	622,961	719,182	1,243,067	1,427,968
Interest expense
Interest expense	245,596	369,053	219,580	714,264
Partnership net income (loss)
Partnership net income (loss)	(453,697)	350,129	192,425	713,704
Total assets
Total assets	49,344,607		49,344,607		49,918,434
Operating Segments [Member] | Other Investments [Member]
Total revenues
Total revenues	1,586,622	1,148,456	3,017,482	2,099,145
Partnership net income (loss)
Partnership net income (loss)	1,578,953	$ 1,148,456	3,000,270	$ 2,099,145
Total assets
Total assets	76,199,168		76,199,168		55,573,834
Consolidation, Eliminations [Member]
Total assets
Total assets	$ (77,536,608)		$ (77,536,608)		$ (56,804,417)