ORGANIZATION AND BUSINESS (Additional Information) (Details)	1 Months Ended
	Nov. 30, 2009	Nov. 18, 2009 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares $ / Baskets $ / Units	Dec. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares	Dec. 31, 2013 $ / shares
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Fee paid by Authorized Purchasers for each order placed to create one or more Creation Baskets or to redeem one or more baskets | $ / Units			350
Number of initially registered units on Form S-1 with the U.S. Securities and Exchange Commission	30,000,000
Net asset value per share | $ / shares		$ 50.00	$ 9.26	$ 11.75	$ 9.72	$ 13.69	$ 13.69
Number of units issued | shares		200,000
Value of unit issued | $		$ 10,000,000
Commenced investment operations date	Nov. 18, 2009
Number of registered units			30,000,000
Creation Baskets [Member]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of units per basket			50,000
Redemption Baskets [Member]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of units per basket			50,000