Statement of Changes in Shareholders' Equity (Unaudited) - USD ($)	Total	General Shares [Member]	Shares [Member]
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	360,832,713		$ 360,832,713
Purchases of Shares - Shares			14,800,000
Redemption of Shares - Value	(386,361,133)		$ (386,361,133)
Redemption of Shares - Shares			(15,800,000)
Net Increase (Decrease) due to Share Transactions, value	(25,528,420)		$ (25,528,420)
Net Increase (Decrease) due to Share Transactions, shares			(1,000,000)
Net Income (Loss)
Net Investment Income (Loss)	3,695,104	$ 6	$ 3,695,098
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	14,607,912	26	14,607,886
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	9,912,096	18	9,912,078
Net Income (Loss)	28,215,112	50	28,215,062
Net Change in Shareholders' Equity, value	2,686,692	50	$ 2,686,642
Net Change in Shareholders' Equity, shares			(1,000,000)
Balance - Value at Sep. 30, 2018	535,414,245	$ 1,010	$ 535,413,235
Balance - Shares at Sep. 30, 2018		40	21,200,000
Balance - Value at Jun. 30, 2018	509,348,559	$ 999	$ 509,347,560
Balance - Shares at Jun. 30, 2018		40	20,400,000
Purchases of Shares - Value	96,054,539		$ 96,054,539
Purchases of Shares - Shares			3,800,000
Redemption of Shares - Value	(75,264,507)		$ (75,264,507)
Redemption of Shares - Shares			(3,000,000)
Net Increase (Decrease) due to Share Transactions, value	20,790,032		$ 20,790,032
Net Increase (Decrease) due to Share Transactions, shares			800,000
Net Income (Loss)
Net Investment Income (Loss)	2,182,346	$ 3	$ 2,182,343
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	4,935,515	11	4,935,504
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	(1,842,207)	(3)	(1,842,204)
Net Income (Loss)	5,275,654	11	5,275,643
Net Change in Shareholders' Equity, value	26,065,686	11	$ 26,065,675
Net Change in Shareholders' Equity, shares			800,000
Balance - Value at Sep. 30, 2018	535,414,245	$ 1,010	$ 535,413,235
Balance - Shares at Sep. 30, 2018		40	21,200,000
Balance - Value at Dec. 31, 2018	494,352,592	$ 1,019	$ 494,351,573
Balance - Shares at Dec. 31, 2018		40	19,400,000
Purchases of Shares - Value	147,608,322		$ 147,608,322
Purchases of Shares - Shares			5,600,000
Redemption of Shares - Value	(332,083,125)		$ (332,083,125)
Redemption of Shares - Shares			(12,800,000)
Net Increase (Decrease) due to Share Transactions, value	(184,474,803)		$ (184,474,803)
Net Increase (Decrease) due to Share Transactions, shares			(7,200,000)
Net Income (Loss)
Net Investment Income (Loss)	4,312,552	$ 14	$ 4,312,538
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	8,251,398	26	8,251,372
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	8,022,329	25	8,022,304
Net Income (Loss)	20,586,279	65	20,586,214
Net Change in Shareholders' Equity, value	(163,888,524)	65	$ (163,888,589)
Net Change in Shareholders' Equity, shares			(7,200,000)
Balance - Value at Sep. 30, 2019	330,464,068	$ 1,084	$ 330,462,984
Balance - Shares at Sep. 30, 2019		40	12,200,000
Balance - Value at Jun. 30, 2019	321,935,385	$ 1,038	$ 321,934,347
Balance - Shares at Jun. 30, 2019		40	12,400,000
Purchases of Shares - Value	85,188,789		$ 85,188,789
Purchases of Shares - Shares			3,200,000
Redemption of Shares - Value	(90,311,144)		$ (90,311,144)
Redemption of Shares - Shares			(3,400,000)
Net Increase (Decrease) due to Share Transactions, value	(5,122,355)		$ (5,122,355)
Net Increase (Decrease) due to Share Transactions, shares			(200,000)
Net Income (Loss)
Net Investment Income (Loss)	1,168,953	$ 5	$ 1,168,948
Net Realized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	6,751,594	22	6,751,572
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations, Affiliated Investments and Currency Futures Contracts	5,730,491	19	5,730,472
Net Income (Loss)	13,651,038	46	13,650,992
Net Change in Shareholders' Equity, value	8,528,683	46	$ 8,528,637
Net Change in Shareholders' Equity, shares			(200,000)
Balance - Value at Sep. 30, 2019	$ 330,464,068	$ 1,084	$ 330,462,984
Balance - Shares at Sep. 30, 2019		40	12,200,000