Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Partner	Shares [Member]
Balance - Value at Dec. 31, 2016	$ 2,557,464,539	$ 633	$ 2,557,463,906
Balance - Shares at Dec. 31, 2016		40	161,600,000
Purchases of Shares - Value	142,251,533		$ 142,251,533
Purchases of Shares - Shares			9,000,000
Redemption of Shares - Value	(708,495,377)		$ (708,495,377)
Redemption of Shares - Shares			(47,000,000)
Net Increase (Decrease) due to Share Transactions, value	(566,243,844)		$ (566,243,844)
Net Increase (Decrease) due to Share Transactions, shares			(38,000,000)
Net Income (Loss)
Net Investment Income (Loss)	(3,590,921)	$ (1)	$ (3,590,920)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(1,224,684)		(1,224,684)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(200,381,016)	(54)	(200,380,962)
Net Income (Loss)	(205,196,621)	(55)	(205,196,566)
Net Change in Shareholders' Equity, value	(771,440,465)	(55)	$ (771,440,410)
Net Change in Shareholders' Equity, shares			(38,000,000)
Balance - Value at Jun. 30, 2017	1,786,024,074	$ 578	$ 1,786,023,496
Balance - Shares at Jun. 30, 2017		40	123,600,000
Balance - Value at Mar. 31, 2017	2,240,788,756	$ 609	$ 2,240,788,147
Balance - Shares at Mar. 31, 2017		40	147,200,000
Purchases of Shares - Value	6,227,072		$ 6,227,072
Purchases of Shares - Shares			400,000
Redemption of Shares - Value	(355,001,530)		$ (355,001,530)
Redemption of Shares - Shares			(24,000,000)
Net Increase (Decrease) due to Share Transactions, value	(348,774,458)		$ (348,774,458)
Net Increase (Decrease) due to Share Transactions, shares			(23,600,000)
Net Income (Loss)
Net Investment Income (Loss)	(1,124,455)		$ (1,124,455)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(63,385,212)	$ (15)	(63,385,197)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(41,480,557)	(16)	(41,480,541)
Net Income (Loss)	(105,990,224)	(31)	(105,990,193)
Net Change in Shareholders' Equity, value	(454,764,682)	(31)	$ (454,764,651)
Net Change in Shareholders' Equity, shares			(23,600,000)
Balance - Value at Jun. 30, 2017	1,786,024,074	$ 578	$ 1,786,023,496
Balance - Shares at Jun. 30, 2017		40	123,600,000
Balance - Value at Dec. 31, 2017	2,262,359,193	$ 665	$ 2,262,358,528
Balance - Shares at Dec. 31, 2017		40	136,000,000
Purchases of Shares - Value	1,064,372,838		$ 1,064,372,838
Purchases of Shares - Shares			61,800,000
Redemption of Shares - Value	(468,642,896)		$ (468,642,896)
Redemption of Shares - Shares			(27,400,000)
Net Increase (Decrease) due to Share Transactions, value	595,729,942		$ 595,729,942
Net Increase (Decrease) due to Share Transactions, shares			34,400,000
Net Income (Loss)
Net Investment Income (Loss)	8,275,760	$ 2	$ 8,275,758
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	149,337,957	41	149,337,916
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(822,825)		(822,825)
Net Income (Loss)	156,790,892	43	156,790,849
Net Change in Shareholders' Equity, value	752,520,834	43	$ 752,520,791
Net Change in Shareholders' Equity, shares			34,400,000
Balance - Value at Jun. 30, 2018	3,014,880,027	$ 708	$ 3,014,879,319
Balance - Shares at Jun. 30, 2018		40	170,400,000
Balance - Value at Mar. 31, 2018	2,759,009,312	$ 678	$ 2,759,008,634
Balance - Shares at Mar. 31, 2018		40	162,800,000
Purchases of Shares - Value	404,777,538		$ 404,777,538
Purchases of Shares - Shares			22,800,000
Redemption of Shares - Value	(264,932,086)		$ (264,932,086)
Redemption of Shares - Shares			(15,200,000)
Net Increase (Decrease) due to Share Transactions, value	139,845,452		$ 139,845,452
Net Increase (Decrease) due to Share Transactions, shares			7,600,000
Net Income (Loss)
Net Investment Income (Loss)	5,644,937	$ 1	$ 5,644,936
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	91,313,535	23	91,313,512
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	19,066,791	6	19,066,785
Net Income (Loss)	116,025,263	30	116,025,233
Net Change in Shareholders' Equity, value	255,870,715	30	$ 255,870,685
Net Change in Shareholders' Equity, shares			7,600,000
Balance - Value at Jun. 30, 2018	$ 3,014,880,027	$ 708	$ 3,014,879,319
Balance - Shares at Jun. 30, 2018		40	170,400,000