Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) Property shares	Dec. 31, 2019 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Cash, FDIC Insured Amount	$ 250,000
Allowance for loan loss	$ 8,305,046	$ 7,393,814		$ 7,393,814
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2019
Accounting standards update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Change in accounting principle, accounting standards update, transition option elected [Extensible List]	us-gaap:AccountingStandardsUpdate201602CumulativeEffectPeriodOfAdoptionMember
Operating leases, right-of-use assets	$ 1,648,742	$ 1,673,242
Property Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Allowance for potential loss	0
Allowance for loan loss	$ 0
Minimum [Member] | Restricted Unit Awards [Member] | Greystone Manager [Member]
Summary Of Significant Accounting Policies [Line Items]
RUAs granted with vesting range	3 months
Minimum [Member] | ATAX Vantage Holdings, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Return on investment period	2 years
Maximum [Member] | RUA and Other Awards [Member] | Greystone Manager [Member]
Summary Of Significant Accounting Policies [Line Items]
Approved grant of restricted units and other awards to employees | shares	3,000,000.0
Maximum [Member] | Restricted Unit Awards [Member] | Greystone Manager [Member]
Summary Of Significant Accounting Policies [Line Items]
Approved grant of restricted units and other awards to employees | shares	3,000,000.0
RUAs granted with vesting range	3 years
Maximum [Member] | ATAX Vantage Holdings, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Return on investment period	3 years
Real Estate Buildings [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of the related asset	19 years
Real Estate Buildings [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of the related asset	40 years
Capital Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of the related asset	5 years
Capital Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of the related asset	15 years
The 5050 MF Property [Member] | ASU 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating leases, right-of-use assets			$ 1,700,000
Operating leases, liabilities for current leases			$ 2,200,000
Lessee operating lease discount rate			6.60%
Greens Hold Co [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of Real Estate Properties | Property	1
Ownership interest percentage in MF property	100.00%