Organization And Business (Additional Information) (Details) (USD $)	1 Months Ended
	Nov. 30, 2009	Nov. 18, 2009	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Feb. 29, 2012 Creation Baskets [Member]	Feb. 29, 2012 Prior to February 29, 2012 [Member] Creation Baskets [Member]	Dec. 31, 2013 Prior to July 1, 2011 [Member]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of units per basket								50,000	100,000
Fee paid by Authorized Purchasers for each order placed to create one or more Creation Baskets or to redeem one or more baskets			350							1,000
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		$ 50.00	$ 18.32	$ 17.23	$ 21.21	$ 35.02	$ 35.02
Number of units issued		200,000
Value of unit issued		$ 10,000,000
Commenced investment operations date		Nov. 18, 2009
Number of registered units			30,000,000