Consolidated Statements of Equity - USD ($)	Total	Common Stock	Capital in Excess of Par Value	Accumulated (Deficit) Income	Accumulated Cash Distributions	Total Stockholders’ Equity	Noncontrolling Interests
Beginning Balance (in shares) at Dec. 31, 2013		15,393,316
Beginning Balance at Dec. 31, 2013	$ 134,378,111	$ 153,933	$ 120,627,485	$ (9,818,401)	$ 0	$ 110,963,017	$ 23,415,094
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Subscriptions received for common stock through public offering (in shares)		5,985,914
Subscriptions received for common stock through public offering	$ 65,396,326	$ 59,859	65,336,467			65,396,326
Redemptions of common stock (in shares)	(40,447)	(40,447)
Redemptions of common stock	$ (400,185)	$ (404)	(399,781)			(400,185)
Stock issuance and offering costs	$ (9,490,715)		(9,490,715)			(9,490,715)
Stock distributions (in shares)	1,187,388	1,187,388
Stock distributions	$ 0	$ 11,874	(11,874)
Purchase of noncontrolling interest	(5,525,825)		(5,269,501)			(5,269,501)	(256,324)
Contributions from non-controlling interests	14,744,367						14,744,367
Distributions to noncontrolling interests	(2,149,737)						(2,149,737)
Net income (loss)	(3,041,409)			(2,189,004)		(2,189,004)	(852,405)
Ending Balance (in shares) at Dec. 31, 2014		22,526,171
Ending Balance at Dec. 31, 2014	193,910,933	$ 225,262	170,792,081	(12,007,405)	0	159,009,938	34,900,995
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions, declared and paid ($3.00 per share)	(67,578,518)				(67,578,518)	(67,578,518)
Contributions from non-controlling interests	1,942,204						1,942,204
Distributions to noncontrolling interests	(62,647,550)						(62,647,550)
Net income (loss)	$ 82,261,459			30,902,630		30,902,630	51,358,829
Ending Balance (in shares) at Dec. 31, 2015	22,526,171	22,526,171
Ending Balance at Dec. 31, 2015	$ 147,888,528	$ 225,262	170,792,081	18,895,225	(67,578,518)	122,334,050	25,554,478
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions to noncontrolling interests	(27,107,808)						(27,107,808)
Net income (loss)	35,462,377			13,530,515		13,530,515	21,931,862
Ending Balance (in shares) at Jul. 31, 2016		22,526,171
Ending Balance at Jul. 31, 2016	$ 156,243,097	$ 225,262	$ 170,792,081	$ 32,425,740	$ (67,578,518)	$ 135,864,565	$ 20,378,532