Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net Income (Loss)	$ 38,849,945	$ (61,705,741)	$ 27,600,800
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Cost of securities purchased	(1,054,042,847)	(1,706,093,799)	(3,297,920,688)
Proceeds from securities sold and matured	1,112,621,356	2,096,851,670	3,531,890,948
Cost of affiliated investments purchased	(722,071,670)	(1,045,572,170)	(583,834,074)
Proceeds from affiliated investments sold	700,995,257	968,029,450	580,047,762
Net accretion of discount on United States Treasury Obligations	(7,771,473)	(4,793,315)	(2,271,490)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments	26,350	7,094	(3,553)
Net change in unrealized (gain) loss on United States Treasury Obligations and Affiliated Investments	(174,316)	331,991	59,876
Change in operating assets and liabilities:
Variation margin- Currency Futures Contracts	(1,561,281)	(739,851)	8,004,212
Dividends from affiliates	(36,013)	(5,890)	(16,819)
Management fees	(36,684)	(171,711)	(195,719)
Brokerage commissions and fees	156	302	382
Net cash provided by (used for) operating activities	66,798,780	246,138,030	263,361,637
Cash flows from financing activities:
Distributions paid to Shareholders	(5,572,383)	(538,669)
Proceeds from purchases of Shares	406,980,619	392,781,258	629,567,756
Redemption of Shares	(462,961,642)	(638,919,288)	(944,874,133)
Increase (decrease) in payable for amount due to custodian, net	(539,669)	538,669	1,000
Net cash provided by (used for) financing activities	(62,093,075)	(246,138,030)	(315,305,377)
Net change in cash	4,705,705		(51,943,740)
Cash at beginning of period	0	0	51,943,740
Cash at end of period	4,705,705	0	0
Supplemental disclosure of cash flow information
Cash paid for interest	$ 20,856	$ 9,086	$ 14,496