Transactions with Related Parties - Additional Information (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) Property	Dec. 31, 2016 USD ($) Property	Dec. 31, 2015 USD ($) Property	Sep. 30, 2013 Property
Rate for administration fees		0.45%
Placement advisory fees				$ 150,000
Outstanding liabilities due to related parties		$ 391,000	$ 415,000
Number of Variable Interest Entities | Property		23	20
Variable Interest Entity Primary Beneficiary [Member]
Number of Real Estate Properties | Property				2
Total Owners [Member] | Variable Interest Entity Primary Beneficiary [Member]
Number of Variable Interest Entities | Property					2
Other Income [Member]
Fees received related to due diligence services performed for sale of properties		$ 128,000
MF Properties Managed [Member]
Number of Real Estate Properties | Property		7
Management fees revenue		$ 390,000	$ 555,000	$ 881,000
Jade Park MF Property [Member]
Exterior rehabilitation services fees paid		63,000
AFCA 2 [Member]
Administrative fees paid by partnership		3,600,000	2,800,000	2,600,000
Investment/mortgage fees received		1,800,000	2,100,000	1,900,000
Administrative fee received	$ 300,000		125,000
Investment/mortgage fees paid by partnership				300,000
Outstanding liabilities due to related parties		3,904,611	3,534,597	2,276,759
AFCA 2 [Member] | Bent Tree [Member]
Administrative fees paid by partnership				635,000
AFCA 2 [Member] | Mortgage Revenue Bonds [Member]
Administrative fees paid by partnership		173,000	95,000	53,000
Farnam Capital Advisors, LLC [Member]
Placement advisory fees		705,000	1,000,000	$ 1,800,000
Consulting fees		$ 921,000	1,200,000
Origination fees			$ 125,000