Debt Financing - Additional Information (Details)	1 Months Ended		12 Months Ended
	Jul. 31, 2019 USD ($)	Aug. 31, 2018 USD ($) Security	Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($) Paydown
Debt Instrument [Line Items]
Amortization of deferred financing costs			$ 1,713,534		$ 1,673,044
Number of unscheduled paydowns for each TEBS | Paydown					3
Term A/B Trust [Member] | Mortgage Revenue Bonds [Member]
Debt Instrument [Line Items]
Deferred financing costs - net		$ 371,000
Variable - M31 [Member]
Debt Instrument [Line Items]
Stated maturities					2024-07
Variable - M31 [Member] | TEBS Financings [Member]
Debt Instrument [Line Items]
Debt instrument additional maturity period			5 years
Debt instrument extended maturity date			2024-07
Stated maturities			2024-07	[1]	2019-07	[2],[3]
Variable - M24 [Member] | TEBS Financings [Member]
Debt Instrument [Line Items]
Interest rate			3.05%
Stated maturities	2027-05				2020-09
Deferred financing costs - net	$ 307,000
Variable - M33 [Member]
Debt Instrument [Line Items]
Stated maturities					2025-07
Variable - M33 [Member] | TEBS Financings [Member]
Debt Instrument [Line Items]
Interest rate			3.24%
Stated maturities	2030-09				2020-07	[2],[4]
Deferred financing costs - net	$ 265,000
Amortization of deferred financing costs	496,000
Premium received upon refinancing of debt	$ 435,000
Fixed - M45 [Member] | TEBS Financings [Member]
Debt Instrument [Line Items]
Stated maturities			2034-07	[5]	2034-07	[6]
Fixed - M45 [Member] | TEBS Financings [Member] | Mortgage Revenue Bonds [Member] | ATAX TEBS IV, LLC [Member]
Debt Instrument [Line Items]
Number of securities provided for long-term debt financing facility | Security		25
Long-term debt financing facility par value		$ 260,600,000
Fixed - M45 [Member] | TEBS Financings [Member] | Class A TEBS Certificates [Member]
Debt Instrument [Line Items]
Long-term debt financing facility par value		$ 221,500,000
Fixed - M45 [Member] | Term A/B Trust [Member] | Mortgage Revenue Bonds [Member]
Debt Instrument [Line Items]
Number of securities collapsed prior to closing of financing | Security		24

[1] Facility fees have a variable component.

[2] Facility fees have a variable component

[3] The Partnership may unilaterally elect to extend the financing for an additional five-year period through July 2024. If the Partnership exercises its extension option, Freddie Mac has the option to adjust components of the Facility Fees

[4] The Partnership may unilaterally elect to extend the financing for an additional five-year period through July 2025. If the Partnership exercises its extension option, Freddie Mac has the option to adjust components of the Facility Fees

[5] The M45 TEBS has an initial interest rate of 3.82% through July 31, 2023. From August 1, 2023 through the stated maturity date, the interest rate is 4.39%. These rates are inclusive of credit enhancement fees payable to Freddie Mac

[6] M45 TEBS has an initial interest rate of 3.82% through July 31, 2023. From August 1, 2023 through the stated maturity date, the interest rate is 4.39%. These rates are inclusive of credit enhancement fees payable to Freddie Mac