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
Sale of Shares - Value	1,155,422,759		$ 1,155,422,759
Sale of Shares - Shares			45,800,000
Redemption of Shares - Value	(985,387,418)		$ (985,387,418)
Redemption of Shares - Shares			(39,200,000)
Net Increase (Decrease) due to Share Transactions, value	170,035,341		$ 170,035,341
Net Increase (Decrease) due to Share Transactions, shares			6,600,000
Net Income (Loss)
Net Investment Income (Loss)	(4,664,360)	$ (4)	$ (4,664,356)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	57,287,829	60	57,287,769
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(14,070,604)	(15)	(14,070,589)
Net Income (Loss)	38,552,865	41	38,552,824
Net Change in Shareholders' Equity, value	208,588,206	41	$ 208,588,165
Net Change in Shareholders' Equity, shares			6,600,000
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
Balance - Value at Mar. 31, 2015	1,338,311,745	$ 1,038	$ 1,338,310,707
Balance - Shares at Mar. 31, 2015		40	51,600,000
Sale of Shares - Value	737,978,146		$ 737,978,146
Sale of Shares - Shares			29,400,000
Redemption of Shares - Value	(813,285,667)		$ (813,285,667)
Redemption of Shares - Shares			(32,400,000)
Net Increase (Decrease) due to Share Transactions, value	(75,307,521)		$ (75,307,521)
Net Increase (Decrease) due to Share Transactions, shares			(3,000,000)
Net Income (Loss)
Net Investment Income (Loss)	(2,532,729)	$ (3)	$ (2,532,726)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(64,699,376)	(51)	(64,699,325)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	19,821,941	16	19,821,925
Net Income (Loss)	(47,410,164)	(38)	(47,410,126)
Net Change in Shareholders' Equity, value	(122,717,685)	(38)	$ (122,717,647)
Net Change in Shareholders' Equity, shares			(3,000,000)
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
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
Sale of Shares - Value	280,127,393		$ 280,127,393
Sale of Shares - Shares			11,400,000
Redemption of Shares - Value	(553,779,990)		$ (553,779,990)
Redemption of Shares - Shares			(22,000,000)
Net Increase (Decrease) due to Share Transactions, value	(273,652,597)		$ (273,652,597)
Net Increase (Decrease) due to Share Transactions, shares			(10,600,000)
Net Income (Loss)
Net Investment Income (Loss)	(2,425,242)	$ (3)	$ (2,425,239)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(32,508,401)	(42)	(32,508,359)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	11,394,178	15	11,394,163
Net Income (Loss)	(23,539,465)	(30)	(23,539,435)
Net Change in Shareholders' Equity, value	(297,192,062)	(30)	$ (297,192,032)
Net Change in Shareholders' Equity, shares			(10,600,000)
Balance - Value at Jun. 30, 2016	836,422,754	$ 996	$ 836,421,758
Balance - Shares at Jun. 30, 2016		40	33,600,000
Balance - Value at Mar. 31, 2016	818,840,473	$ 981	$ 818,839,492
Balance - Shares at Mar. 31, 2016		40	33,400,000
Sale of Shares - Value	82,936,935		$ 82,936,935
Sale of Shares - Shares			3,400,000
Redemption of Shares - Value	(78,814,935)		$ (78,814,935)
Redemption of Shares - Shares			(3,200,000)
Net Increase (Decrease) due to Share Transactions, value	4,122,000		$ 4,122,000
Net Increase (Decrease) due to Share Transactions, shares			200,000
Net Income (Loss)
Net Investment Income (Loss)	(1,079,945)	$ (2)	$ (1,079,943)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(21,264,577)	(28)	(21,264,549)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	35,804,803	45	35,804,758
Net Income (Loss)	13,460,281	15	13,460,266
Net Change in Shareholders' Equity, value	17,582,281	15	$ 17,582,266
Net Change in Shareholders' Equity, shares			200,000
Balance - Value at Jun. 30, 2016	$ 836,422,754	$ 996	$ 836,421,758
Balance - Shares at Jun. 30, 2016		40	33,600,000