Statements of Financial Condition (Unaudited) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Assets
United States Treasury Obligations, at value (cost $700,649,162 and $846,190,082, respectively)	$ 700,599,334	$ 846,158,812
Affiliated investments, at value and cost	33,096,938	3,786,312
Total Investments, at value (cost $733,746,100 and $849,976,394, respectively)	733,696,272	849,945,124
Receivable for:
Variation margin	2,805,408
Dividends from affiliates	17,730	16,819
Total assets	736,519,410	849,961,943
Payable for:
Variation margin		3,514,750
Due to custodian		1,000
Management fee	483,698	532,758
Brokerage commissions and fees	4,468	4,196
Total liabilities	488,166	4,052,704
Commitments and Contingencies (Note 9)
Equity
Shareholder's equity—General Shares	1,037	1,057
Shareholders' equity—Shares	736,030,207	845,908,182
Total shareholders' equity	736,031,244	845,909,239
Total liabilities and equity	$ 736,519,410	$ 849,961,943
General Shares outstanding	40	40
Shares outstanding	28,400,000	32,000,000
Net asset value per share	$ 25.92	$ 26.43
Market value per share	$ 25.95	$ 26.45