Statements of Assets and Liabilities - USD ($)		Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents		$ 7,739,749	$ 12,009,679	[1]
Short-term investments(b)	[2]	585,678,148	731,918,274	[1]
Short-term investments held at brokers (restricted)(c)	[3]	66,250,236	52,853,943	[1]
Receivable for capital Shares sold		0	2,136,010	[1]
Receivable for variation margin on open futures contracts (Note 9)		6,701,406	0	[1]
Total Assets		666,369,539	798,917,906	[1]
Liabilities
Payable for variation margin on open futures contracts (Note 9)		0	7,717,674	[1]
Payable for capital shares redeemed		0	3,231,307	[1]
Due to brokers		0	323,566	[1]
Sponsor's fees payable		430,292	525,593	[1]
Total Liabilities		$ 430,292	$ 11,798,140	[1]
Commitments and contingent liabilities (Note 7)
Net Assets		$ 665,939,247	$ 787,119,766	[1],[4]
Shares issued and outstanding(d) (in Shares)	[5]	46,850,000	36,850,000	[1]
Net Asset Value per Share (Note 2G) (in Dollars per share)		$ 14.21	$ 21.36	[1]

[1] Previously reported as "Statements of Financial Condition." Please refer to Note 2A.

[2] Cost of short-term investments: $585,650,805 and $731,902,394, respectively.

[3] Cost of short-term investments held at brokers (restricted): $66,255,130 and $52,852,591, respectively.

[4] Previously reported as "Statements of Changes in Shareholders' Capital." Please refer to Note 2A.

[5] No par value, unlimited amount authorized.