Notes Payable and Accrued Interest (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Notes Payable and Accrued Interest [Abstract]
Notes payable and accrued interest	$ 108,352,400			$ 108,352,400		$ 77,527,300
Credit Facility [Abstract]
Impairment charges	11,718,700	6,800,000	0	18,518,700	0
Credit Facility [Member]
Notes Payable and Accrued Interest [Abstract]
Credit Facility principal	108,200,000			108,200,000		77,500,000
Credit Facility accrued interest	152,400			152,400		27,300
Notes payable and accrued interest	108,352,400			108,352,400		77,527,300
Credit Facility [Abstract]
Credit facility, borrowing capacity replaced	130,000,000			130,000,000
Credit faclity	150,000,000			150,000,000
Credit facility maximum borrowing capacity replaced	200,000,000			200,000,000
Credit facility maximum borrowing capacity	180,000,000			180,000,000
Expiration date				May 31, 2019
Unused amount of the credit facility	$ 71,800,000			$ 71,800,000		$ 52,500,000
Weighted average interest rate on credit facility (in hundredths)	3.59%			3.59%		3.94%
Number of participant lenders departed				2