Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) | Total | General Shares [Member] | Shares [Member] |
Balance - Value at Dec. 31, 2015 | $ 93,692,074 | $ 446 | $ 93,691,628 |
Balance - Shares at Dec. 31, 2015 | | 40 | 8,400,000 |
Purchases of Shares - Value | 98,199,197 | | $ 98,199,197 |
Purchases of Shares - Shares | | | 8,200,000 |
Redemption of Shares - Value | (40,395,619) | | $ (40,395,619) |
Redemption of Shares - Shares | | | (3,800,000) |
Net Increase (Decrease) due to Share Transactions, value | 57,803,578 | | $ 57,803,578 |
Net Increase (Decrease) due to Share Transactions, shares | | | 4,400,000 |
Net Income (Loss) | | | |
Net Investment Income (Loss) | (235,531) | $ (2) | $ (235,529) |
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (25,173,759) | (154) | (25,173,605) |
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | 34,547,052 | 212 | 34,546,840 |
Net Income (Loss) | 9,137,762 | 56 | 9,137,706 |
Net Change in Shareholders' Equity, value | 66,941,340 | 56 | $ 66,941,284 |
Net Change in Shareholders' Equity, shares | | | 4,400,000 |
Balance - Value at Jun. 30, 2016 | 160,633,414 | $ 502 | $ 160,632,912 |
Balance - Shares at Jun. 30, 2016 | | 40 | 12,800,000 |
Balance - Value at Mar. 31, 2016 | 75,431,679 | $ 419 | $ 75,431,260 |
Balance - Shares at Mar. 31, 2016 | | 40 | 7,200,000 |
Purchases of Shares - Value | 88,828,628 | | $ 88,828,628 |
Purchases of Shares - Shares | | | 7,200,000 |
Redemption of Shares - Value | (18,977,306) | | $ (18,977,306) |
Redemption of Shares - Shares | | | (1,600,000) |
Net Increase (Decrease) due to Share Transactions, value | 69,851,322 | | $ 69,851,322 |
Net Increase (Decrease) due to Share Transactions, shares | | | 5,600,000 |
Net Income (Loss) | | | |
Net Investment Income (Loss) | (124,568) | $ (1) | $ (124,567) |
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (3,278,845) | (59) | (3,278,786) |
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | 18,753,826 | 143 | 18,753,683 |
Net Income (Loss) | 15,350,413 | 83 | 15,350,330 |
Net Change in Shareholders' Equity, value | 85,201,735 | 83 | $ 85,201,652 |
Net Change in Shareholders' Equity, shares | | | 5,600,000 |
Balance - Value at Jun. 30, 2016 | 160,633,414 | $ 502 | $ 160,632,912 |
Balance - Shares at Jun. 30, 2016 | | 40 | 12,800,000 |
Balance - Value at Dec. 31, 2016 | 193,214,737 | $ 552 | $ 193,214,185 |
Balance - Shares at Dec. 31, 2016 | | 40 | 14,000,000 |
Purchases of Shares - Value | 42,456,525 | | $ 42,456,525 |
Purchases of Shares - Shares | | | 3,200,000 |
Redemption of Shares - Value | (107,909,734) | | $ (107,909,734) |
Redemption of Shares - Shares | | | (8,600,000) |
Net Increase (Decrease) due to Share Transactions, value | (65,453,209) | | $ (65,453,209) |
Net Increase (Decrease) due to Share Transactions, shares | | | (5,400,000) |
Net Income (Loss) | | | |
Net Investment Income (Loss) | (180,659) | $ (1) | $ (180,658) |
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (5,311,867) | (16) | (5,311,851) |
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (22,564,953) | (71) | (22,564,882) |
Net Income (Loss) | (28,057,479) | (88) | (28,057,391) |
Net Change in Shareholders' Equity, value | (93,510,688) | (88) | $ (93,510,600) |
Net Change in Shareholders' Equity, shares | | | (5,400,000) |
Balance - Value at Jun. 30, 2017 | 99,704,049 | $ 464 | $ 99,703,585 |
Balance - Shares at Jun. 30, 2017 | | 40 | 8,600,000 |
Balance - Value at Mar. 31, 2017 | 146,006,760 | $ 504 | $ 146,006,256 |
Balance - Shares at Mar. 31, 2017 | | 40 | 11,600,000 |
Purchases of Shares - Value | 23,600,261 | | $ 23,600,261 |
Purchases of Shares - Shares | | | 1,800,000 |
Redemption of Shares - Value | (58,030,733) | | $ (58,030,733) |
Redemption of Shares - Shares | | | (4,800,000) |
Net Increase (Decrease) due to Share Transactions, value | (34,430,472) | | $ (34,430,472) |
Net Increase (Decrease) due to Share Transactions, shares | | | (3,000,000) |
Net Income (Loss) | | | |
Net Investment Income (Loss) | (45,619) | | $ (45,619) |
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (7,406,253) | $ (22) | (7,406,231) |
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts | (4,420,367) | (18) | (4,420,349) |
Net Income (Loss) | (11,872,239) | (40) | (11,872,199) |
Net Change in Shareholders' Equity, value | (46,302,711) | (40) | $ (46,302,671) |
Net Change in Shareholders' Equity, shares | | | (3,000,000) |
Balance - Value at Jun. 30, 2017 | $ 99,704,049 | $ 464 | $ 99,703,585 |
Balance - Shares at Jun. 30, 2017 | | 40 | 8,600,000 |