Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Shares [Member]	Shares [Member]
Balance - Value at Dec. 31, 2015	$ 1,133,614,816	$ 1,026	$ 1,133,613,790
Balance - Shares at Dec. 31, 2015		40	44,200,000
Purchases of Shares - Value	368,777,500		$ 368,777,500
Purchases of Shares - Shares			15,000,000
Redemption of Shares - Value	(731,595,884)		$ (731,595,884)
Redemption of Shares - Shares			(29,200,000)
Net Increase (Decrease) due to Share Transactions, value	(362,818,384)		$ (362,818,384)
Net Increase (Decrease) due to Share Transactions, shares			(14,200,000)
Net Income (Loss)
Net Investment Income (Loss)	(3,431,969)	$ (4)	$ (3,431,965)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(18,590,392)	(24)	(18,590,368)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(8,705,462)	(11)	(8,705,451)
Net Income (Loss)	(30,727,823)	(39)	(30,727,784)
Net Change in Shareholders' Equity, value	(393,546,207)	(39)	$ (393,546,168)
Net Change in Shareholders' Equity, shares			(14,200,000)
Balance - Value at Sep. 30, 2016	740,068,609	$ 987	$ 740,067,622
Balance - Shares at Sep. 30, 2016		40	30,000,000
Balance - Value at Jun. 30, 2016	836,422,754	$ 996	$ 836,421,758
Balance - Shares at Jun. 30, 2016		40	33,600,000
Purchases of Shares - Value	88,650,107		$ 88,650,107
Purchases of Shares - Shares			3,600,000
Redemption of Shares - Value	(177,815,894)		$ (177,815,894)
Redemption of Shares - Shares			(7,200,000)
Net Increase (Decrease) due to Share Transactions, value	(89,165,787)		$ (89,165,787)
Net Increase (Decrease) due to Share Transactions, shares			(3,600,000)
Net Income (Loss)
Net Investment Income (Loss)	(1,006,727)	$ (1)	$ (1,006,726)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	13,918,009	18	13,917,991
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(20,099,640)	(26)	(20,099,614)
Net Income (Loss)	(7,188,358)	(9)	(7,188,349)
Net Change in Shareholders' Equity, value	(96,354,145)	(9)	$ (96,354,136)
Net Change in Shareholders' Equity, shares			(3,600,000)
Balance - Value at Sep. 30, 2016	740,068,609	$ 987	$ 740,067,622
Balance - Shares at Sep. 30, 2016		40	30,000,000
Balance - Value at Dec. 31, 2016	845,909,239	$ 1,057	$ 845,908,182
Balance - Shares at Dec. 31, 2016		40	32,000,000
Purchases of Shares - Value	348,453,118		$ 348,453,118
Purchases of Shares - Shares			14,000,000
Redemption of Shares - Value	(483,477,960)		$ (483,477,960)
Redemption of Shares - Shares			(19,000,000)
Net Increase (Decrease) due to Share Transactions, value	(135,024,842)		$ (135,024,842)
Net Increase (Decrease) due to Share Transactions, shares			(5,000,000)
Net Income (Loss)
Net Investment Income (Loss)	(334,462)	$ (1)	$ (334,461)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(62,463,907)	(96)	(62,463,811)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	4,471,197	7	4,471,190
Net Income (Loss)	(58,327,172)	(90)	(58,327,082)
Net Change in Shareholders' Equity, value	(193,352,014)	(90)	$ (193,351,924)
Net Change in Shareholders' Equity, shares			(5,000,000)
Balance - Value at Sep. 30, 2017	652,557,225	$ 967	$ 652,556,258
Balance - Shares at Sep. 30, 2017		40	27,000,000
Balance - Value at Jun. 30, 2017	539,604,740	$ 990	$ 539,603,750
Balance - Shares at Jun. 30, 2017		40	21,800,000
Purchases of Shares - Value	202,926,916		$ 202,926,916
Purchases of Shares - Shares			8,400,000
Redemption of Shares - Value	(77,668,762)		$ (77,668,762)
Redemption of Shares - Shares			(3,200,000)
Net Increase (Decrease) due to Share Transactions, value	125,258,154		$ 125,258,154
Net Increase (Decrease) due to Share Transactions, shares			5,200,000
Net Income (Loss)
Net Investment Income (Loss)	250,879		$ 250,879
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(26,817,213)	$ (44)	(26,817,169)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	14,260,665	21	14,260,644
Net Income (Loss)	(12,305,669)	(23)	(12,305,646)
Net Change in Shareholders' Equity, value	112,952,485	(23)	$ 112,952,508
Net Change in Shareholders' Equity, shares			5,200,000
Balance - Value at Sep. 30, 2017	$ 652,557,225	$ 967	$ 652,556,258
Balance - Shares at Sep. 30, 2017		40	27,000,000