Investments in Unconsolidated Entities - Additional Information (Details) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended
	Aug. 31, 2021	May 31, 2021	Mar. 31, 2021	Jun. 30, 2020	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2021	Apr. 30, 2021	Aug. 31, 2020	Jan. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Gain on sale of investments in unconsolidated entities					$ 6,954,649		$ 15,227,239
Vantage At Germantown [Member]
Schedule Of Equity Method Investments [Line Items]
Cash received			$ 16,100,000
Income on sale of properties			862,000
Gain on sale of investments in unconsolidated entities			$ 2,800,000
Vantage at Loveland [Member]
Schedule Of Equity Method Investments [Line Items]
Equity commitment of fund construction								$ 16,300,000
Increase in equity commitment of fund construction upon certain events								$ 18,200,000
Vantage at Helotes [Member]
Schedule Of Equity Method Investments [Line Items]
Equity commitment of fund construction		$ 12,600,000
Vantage At Powdersville [Member]
Schedule Of Equity Method Investments [Line Items]
Cash received		20,100,000
Income on sale of properties		2,400,000
Gain on sale of investments in unconsolidated entities		$ 5,500,000
Vantage At Bulverde [Member]
Schedule Of Equity Method Investments [Line Items]
Cash received	$ 18,900,000
Income on sale of properties	1,400,000
Gain on sale of investments in unconsolidated entities	$ 7,000,000.0
Vantage At Fair Oaks [Member]
Schedule Of Equity Method Investments [Line Items]
Equity commitment of fund construction					$ 11,000,000.0		$ 11,000,000.0
Vantage At Westover Hills [Member]
Schedule Of Equity Method Investments [Line Items]
Equity commitment of fund construction										$ 7,300,000
Vantage at Waco [Member]
Schedule Of Equity Method Investments [Line Items]
Cash received				$ 10,600,000
Income on sale of properties				$ 1,300,000		$ 201,000
Vantage At Tomball [Member]
Schedule Of Equity Method Investments [Line Items]
Equity commitment of fund construction									$ 10,400,000
ATAX Vantage Holdings, LLC [Member] | Minimum [Member]
Schedule Of Equity Method Investments [Line Items]
Return on investment period							2 years
ATAX Vantage Holdings, LLC [Member] | Maximum [Member]
Schedule Of Equity Method Investments [Line Items]
Return on investment period							3 years