Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Shares [Member]	Shares [Member]
Balance - Value at Dec. 31, 2016	$ 32,749,139	$ 819	$ 32,748,320
Balance - Shares at Dec. 31, 2016		40	1,600,000
Purchases of Shares - Value	17,399,984		$ 17,399,984
Purchases of Shares - Shares			800,000
Redemption of Shares - Value	(4,430,431)		$ (4,430,431)
Redemption of Shares - Shares			(200,000)
Net Increase (Decrease) due to Share Transactions, value	12,969,553		$ 12,969,553
Net Increase (Decrease) due to Share Transactions, shares			600,000
Net Income (Loss)
Net Investment Income (Loss)	5,732		$ 5,732
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	3,947,381	$ 87	3,947,294
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(619,728)	(14)	(619,714)
Net Income (Loss)	3,333,385	73	3,333,312
Net Change in Shareholders' Equity, value	16,302,938	73	$ 16,302,865
Net Change in Shareholders' Equity, shares			600,000
Balance - Value at Sep. 30, 2017	49,052,077	$ 892	$ 49,051,185
Balance - Shares at Sep. 30, 2017		40	2,200,000
Balance - Value at Jun. 30, 2017	43,582,327	$ 872	$ 43,581,455
Balance - Shares at Jun. 30, 2017		40	2,000,000
Purchases of Shares - Value	8,986,559		$ 8,986,559
Purchases of Shares - Shares			400,000
Redemption of Shares - Value	(4,430,431)		$ (4,430,431)
Redemption of Shares - Shares			(200,000)
Net Increase (Decrease) due to Share Transactions, value	4,556,128		$ 4,556,128
Net Increase (Decrease) due to Share Transactions, shares			200,000
Net Income (Loss)
Net Investment Income (Loss)	29,095	$ 1	$ 29,094
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	2,038,819	45	2,038,774
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(1,154,292)	(26)	(1,154,266)
Net Income (Loss)	913,622	20	913,602
Net Change in Shareholders' Equity, value	5,469,750	20	$ 5,469,730
Net Change in Shareholders' Equity, shares			200,000
Balance - Value at Sep. 30, 2017	49,052,077	$ 892	$ 49,051,185
Balance - Shares at Sep. 30, 2017		40	2,200,000
Balance - Value at Dec. 31, 2017	40,371,178	$ 897	$ 40,370,281
Balance - Shares at Dec. 31, 2017		40	1,800,000
Purchases of Shares - Value	82,701,350		$ 82,701,350
Purchases of Shares - Shares			3,800,000
Redemption of Shares - Value	(91,155,823)		$ (91,155,823)
Redemption of Shares - Shares			(4,200,000)
Net Increase (Decrease) due to Share Transactions, value	(8,454,473)		$ (8,454,473)
Net Increase (Decrease) due to Share Transactions, shares			(400,000)
Net Income (Loss)
Net Investment Income (Loss)	264,284	$ 5	$ 264,279
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(1,356,066)	(27)	(1,356,039)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(690,213)	(14)	(690,199)
Net Income (Loss)	(1,781,995)	(36)	(1,781,959)
Net Change in Shareholders' Equity, value	(10,236,468)	(36)	$ (10,236,432)
Net Change in Shareholders' Equity, shares			(400,000)
Balance - Value at Sep. 30, 2018	30,134,710	$ 861	$ 30,133,849
Balance - Shares at Sep. 30, 2018		40	1,400,000
Balance - Value at Jun. 30, 2018	34,637,917	$ 866	$ 34,637,051
Balance - Shares at Jun. 30, 2018		40	1,600,000
Purchases of Shares - Value	47,577,235		$ 47,577,235
Purchases of Shares - Shares			2,200,000
Redemption of Shares - Value	(51,835,782)		$ (51,835,782)
Redemption of Shares - Shares			(2,400,000)
Net Increase (Decrease) due to Share Transactions, value	(4,258,547)		$ (4,258,547)
Net Increase (Decrease) due to Share Transactions, shares			(200,000)
Net Income (Loss)
Net Investment Income (Loss)	101,670	$ 2	$ 101,668
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(353,877)	(7)	(353,870)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	7,547		7,547
Net Income (Loss)	(244,660)	(5)	(244,655)
Net Change in Shareholders' Equity, value	(4,503,207)	(5)	$ (4,503,202)
Net Change in Shareholders' Equity, shares			(200,000)
Balance - Value at Sep. 30, 2018	$ 30,134,710	$ 861	$ 30,133,849
Balance - Shares at Sep. 30, 2018		40	1,400,000