Fair Value Measurements Fair Market Value of Liabilities (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Mortgages payable and other secured financing	$ 51,379,512	$ 69,247,574
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Debt financing and LOCs	555,199,700	468,993,716
Mortgages payable and other secured financing	51,379,512	69,247,574
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Debt financing and LOCs	553,083,924	475,415,345
Mortgages payable and other secured financing	$ 51,595,281	$ 67,735,213