PHC Certificates - Schedule of Investments in PHC Certificates (Details) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value, held in trust	$ 77,971,208	$ 90,016,872
Public housing capital fund trusts [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis, Held in Trust	50,167,034	56,801,062
Cumulative Unrealized Gain, held in trust		756,853
Cumulative Unrealized Loss, held in trust	(525,446)	(399,847)
Estimated Fair Value, held in trust	49,641,588	57,158,068
Public Housing Capital Fund Trust I [Member] \| Public housing capital fund trusts [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis, Held in Trust	25,109,305	26,077,158
Cumulative Unrealized Gain, held in trust		672,097
Estimated Fair Value, held in trust	$ 25,109,305	$ 26,749,255
Public Housing Capital Fund Trust I [Member] \| Public housing capital fund trusts [Member] \| Standard & Poor's, AA- Rating [Member]
Schedule Of Available For Sale Securities [Line Items]
Weighted Average Lives (Years)	7 years 3 months 21 days	8 years 3 months 22 days
Investment Rating	AA-	AA-
Weighted Average Interest Rate Over Life	5.39%	5.36%
Public Housing Capital Fund Trust II [Member] \| Public housing capital fund trusts [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis, Held in Trust	$ 9,606,480	$ 10,600,967
Cumulative Unrealized Gain, held in trust		84,756
Cumulative Unrealized Loss, held in trust	(248,189)
Estimated Fair Value, held in trust	$ 9,358,291	$ 10,685,723
Public Housing Capital Fund Trust II [Member] \| Public housing capital fund trusts [Member] \| Standard & Poor's, A+ Rating [Member]
Schedule Of Available For Sale Securities [Line Items]
Weighted Average Lives (Years)	6 years 4 months 13 days	7 years 7 months 24 days
Investment Rating	A+	A+
Weighted Average Interest Rate Over Life	4.32%	4.31%
Public Housing Capital Fund Trust III [Member] \| Public housing capital fund trusts [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis, Held in Trust	$ 15,451,249	$ 20,122,937
Cumulative Unrealized Loss, held in trust	(277,257)	(399,847)
Estimated Fair Value, held in trust	$ 15,173,992	$ 19,723,090
Public Housing Capital Fund Trust III [Member] \| Public housing capital fund trusts [Member] \| Standard & Poor's, BBB Rating [Member]
Schedule Of Available For Sale Securities [Line Items]
Weighted Average Lives (Years)	7 years 7 months 9 days	8 years 9 months 14 days
Investment Rating	BBB	BBB
Weighted Average Interest Rate Over Life	5.23%	5.42%

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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