Notes Payable and Accrued Interest (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Notes payable and accrued interest [Abstract]
Unamortized debt issuance costs	$ (2,814,000)	$ (4,104,400)
Notes payable and accrued interest	107,621,600	129,486,200
Credit Facility [Member]
Notes payable and accrued interest [Abstract]
Credit Facility principal	110,400,000	133,400,000
Unamortized debt issuance costs	(2,814,000)	(4,104,400)
Credit Facility accrued interest	35,600	190,600
Notes payable and accrued interest	107,621,600	129,486,200
Credit Facility [Abstract]
Credit facility maximum borrowing capacity	150,000,000
Credit facility potential maximum borrowing capacity	180,000,000
Unused amount of the credit facility	$ 39,600,000	$ 16,600,000
Weighted average interest rate on credit facility	3.80%	3.58%