Schedule III - Real Estate and Accumulated Depreciation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Balance at January 1	$ 65,436,739	$ 58,856,688	$ 68,589,778
Current year depreciation expense	8,361,698	6,930,145	5,726,319
Disposition of real estate	(14,708,586)	(350,094)	(15,459,409)
Balance at December 31	$ 59,089,851	$ 65,436,739	$ 58,856,688