Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Shares [Member]	Shares [Member]
Balance - Value at Dec. 31, 2014	$ 1,007,005,854	$ 959	$ 1,007,004,895
Balance - Shares at Dec. 31, 2014		40	42,000,000
Purchases of Shares - Value	1,565,254,163		$ 1,565,254,163
Purchases of Shares - Shares			62,000,000
Redemption of Shares - Value	(1,573,960,328)		$ (1,573,960,328)
Redemption of Shares - Shares			(62,600,000)
Net Increase (Decrease) due to Share Transactions, value	(8,706,165)		$ (8,706,165)
Net Increase (Decrease) due to Share Transactions, shares			(600,000)
Net Income (Loss)
Net Investment Income (Loss)	(6,955,688)	$ (8)	$ (6,955,680)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	62,948,929	69	62,948,860
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(14,027,827)	(15)	(14,027,812)
Net Income (Loss)	41,965,414	46	41,965,368
Net Change in Shareholders' Equity, value	33,259,249	46	$ 33,259,203
Net Change in Shareholders' Equity, shares			(600,000)
Balance - Value at Sep. 30, 2015	1,040,265,103	$ 1,005	$ 1,040,264,098
Balance - Shares at Sep. 30, 2015		40	41,400,000
Balance - Value at Jun. 30, 2015	1,215,594,060	$ 1,000	$ 1,215,593,060
Balance - Shares at Jun. 30, 2015		40	48,600,000
Purchases of Shares - Value	409,831,404		$ 409,831,404
Purchases of Shares - Shares			16,200,000
Redemption of Shares - Value	(588,572,910)		$ (588,572,910)
Redemption of Shares - Shares			(23,400,000)
Net Increase (Decrease) due to Share Transactions, value	(178,741,506)		$ (178,741,506)
Net Increase (Decrease) due to Share Transactions, shares			(7,200,000)
Net Income (Loss)
Net Investment Income (Loss)	(2,291,328)	$ (4)	$ (2,291,324)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	5,661,100	9	5,661,091
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	42,777		42,777
Net Income (Loss)	3,412,549	5	3,412,544
Net Change in Shareholders' Equity, value	(175,328,957)	5	$ (175,328,962)
Net Change in Shareholders' Equity, shares			(7,200,000)
Balance - Value at Sep. 30, 2015	1,040,265,103	$ 1,005	$ 1,040,264,098
Balance - Shares at Sep. 30, 2015		40	41,400,000
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 and Currency Futures Contracts	(18,590,392)	(24)	(18,590,368)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations 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 and Currency Futures Contracts	13,918,009	18	13,917,991
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations 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