Unaudited Statements of Financial Condition (USD $)	Jun. 30, 2014	Dec. 31, 2013
Assets
United States Treasury Obligations, at fair value (cost $374,984,606 and $282,977,856 respectively)	$ 374,990,428	$ 282,986,507
Cash held by commodity broker	3,591,743	3,113,981
Net unrealized appreciation (depreciation) on commodity futures contracts	21,250,208	13,354,799
Equity in broker trading account	399,832,379	299,455,287
Total assets	399,832,379	299,455,287
Liabilities
Payable for securities purchased	30,997,257	30,994,907
Management fee payable	225,981	171,407
Brokerage fee payable	2,892	5,372
Total liabilities	31,226,130	31,171,686
Commitments and Contingencies (Note 8)
Equity
Shareholders' equity-General Shares	1,229	1,166
Shareholders' equity-Shares	368,605,020	268,282,435
Total shareholders' equity	368,606,249	268,283,601
Total liabilities and equity	$ 399,832,379	$ 299,455,287
General Shares outstanding	40	40
Shares outstanding	12,000,000	9,200,000
Net asset value per share
General Shares	$ 30.72	$ 29.16
Shares	$ 30.72	$ 29.16