Loans - Secured Loans by Lien Position in the Collateral (Details)		3 Months Ended	12 Months Ended
		Mar. 31, 2018 USD ($) MortgageLoan	Dec. 31, 2017 USD ($) MortgageLoan
Loans (Details) - Secured Loans by Lien Position in the Collateral [Line Items]
Loans | MortgageLoan		93	93
Loans - principal (in Dollars)		$ 57,865,391	$ 54,768,689
Liens due other lenders at loan closing		37,901,684	31,545,806
Total debt		95,767,075	86,314,495
Appraised property value at loan closing		$ 197,444,000	$ 181,018,000
Percent of total debt to appraised values (LTV) at loan closing	[1]	53.70%	53.50%
Loans - percent		100.00%	100.00%
First Trust Deeds [Member]
Loans (Details) - Secured Loans by Lien Position in the Collateral [Line Items]
Loans | MortgageLoan		56	60
Loans - principal (in Dollars)		$ 35,087,060	$ 37,032,195
Loans - percent		61.00%	68.00%
Second Trust Deeds [Member]
Loans (Details) - Secured Loans by Lien Position in the Collateral [Line Items]
Loans | MortgageLoan		37	33
Loans - principal (in Dollars)		$ 22,778,331	$ 17,736,494
Loans - percent		39.00%	32.00%

[1] Based on appraised values and liens due other lenders at loan closing. The weighted-average loan-to-value (LTV) computation above does not take into account subsequent increases or decreases in property values following the loan closing nor does it include decreases or increases of the amount owing on senior liens to other lenders.