Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Shares [Member]	Shares [Member]
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	103,691,677		$ 103,691,677
Purchases of Shares - Shares			4,000,000
Redemption of Shares - Value	(197,257,364)		$ (197,257,364)
Redemption of Shares - Shares			(7,600,000)
Net Increase (Decrease) due to Share Transactions, value	(93,565,687)		$ (93,565,687)
Net Increase (Decrease) due to Share Transactions, shares			(3,600,000)
Net Income (Loss)
Net Investment Income (Loss)	(528,048)	$ (1)	$ (528,047)
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(3,237,381)	(4)	(3,237,377)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(12,546,879)	(15)	(12,546,864)
Net Income (Loss)	(16,312,308)	(20)	(16,312,288)
Net Change in Shareholders' Equity, value	(109,877,995)	(20)	$ (109,877,975)
Net Change in Shareholders' Equity, shares			(3,600,000)
Balance - Value at Mar. 31, 2017	736,031,244	$ 1,037	$ 736,030,207
Balance - Shares at Mar. 31, 2017		40	28,400,000
Balance - Value at Dec. 31, 2017	532,727,553	$ 960	$ 532,726,593
Balance - Shares at Dec. 31, 2017		40	22,200,000
Purchases of Shares - Value	69,990,564		$ 69,990,564
Purchases of Shares - Shares			3,000,000
Redemption of Shares - Value	(94,258,632)		$ (94,258,632)
Redemption of Shares - Shares			(4,000,000)
Net Increase (Decrease) due to Share Transactions, value	(24,268,068)		$ (24,268,068)
Net Increase (Decrease) due to Share Transactions, shares			(1,000,000)
Net Income (Loss)
Net Investment Income (Loss)	573,645	$ 1	$ 573,644
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(18,728,677)	(37)	(18,728,640)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	10,517,692	21	10,517,671
Net Income (Loss)	(7,637,340)	(15)	(7,637,325)
Net Change in Shareholders' Equity, value	(31,905,408)	(15)	$ (31,905,393)
Net Change in Shareholders' Equity, shares			(1,000,000)
Balance - Value at Mar. 31, 2018	$ 500,822,145	$ 945	$ 500,821,200
Balance - Shares at Mar. 31, 2018		40	21,200,000