QUARTERLY FINANCIAL DATA (Unaudited) (Quarterly Financial Information Presents The Results Of Operations) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Data [Line Items]
Total income (loss)	$ (645,188)	$ 9,809	$ (536,427)	$ (1,880,112)	$ 2,343,019	$ (673,185)	$ 2,659,703	$ (1,337,347)	$ (3,051,918)	$ 2,992,190	$ (4,405,715)
Total expenses	36,482	40,970	33,306	45,520	59,503	61,441	53,295	50,619	156,278	224,858	231,820
Expense waivers	(17,165)	(19,588)	(9,907)	(15,053)	(25,375)	(28,986)	(24,115)	(23,616)	61,713	102,092	89,122
Net expenses	19,317	21,382	23,399	30,467	34,128	32,455	29,180	27,003	94,565	122,766	142,698
Net income (loss)	$ (664,505)	$ (11,573)	$ (559,826)	$ (1,910,579)	$ 2,308,891	$ (705,640)	$ 2,630,523	$ (1,364,350)	$ (3,146,483)	$ 2,869,424	$ (4,548,413)
Net income (loss) per share	$ (0.75)	$ (0.01)	$ (0.63)	$ (1.1)	$ 1.61	$ (0.5)	$ 1.9	$ (0.98)	$ (2.49)	$ 2.03	$ (3.97)