Transactions with Related Parties - Summary of Transactions Between Borrowers of Partnership's MRBs and Affiliates (Details) - General Partner [Member] - USD ($)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Non-partnership property administrative fee received	[1]	$ 36,000	$ 69,000
Investment/mortgage fees received	[2]	$ 1,362,000	2,873,000
Mortgage Revenue Bonds [Member]
Redemption administrative fee	[3]		$ 283,000

[1] AFCA 2 received administrative fees directly from the owners of certain properties financed by certain MRBs held by the Partnership.  These administrative fees equal 0.45% per annum of the outstanding principal balance of the MRBs. The disclosed amounts represent administrative fees received by AFCA 2 during the periods specified.

[2] AFCA 2 received placement fees in connection with the acquisition of certain MRBs and investments in unconsolidated entities.

[3] AFCA 2 received one-time administrative fees related to early redemptions of the Lake Forest MRB in September 2018 and the Vantage at Judson MRBs in December 2018.