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	417,444,613		$ 417,444,613
Sale of Shares - Shares			16,400,000
Redemption of Shares - Value	(172,101,751)		$ (172,101,751)
Redemption of Shares - Shares			(6,800,000)
Net Increase (Decrease) due to Share Transactions, value	245,342,862		$ 245,342,862
Net Increase (Decrease) due to Share Transactions, shares			9,600,000
Net Income (Loss)
Net Investment Income (Loss)	(2,131,631)	$ (1)	$ (2,131,630)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	121,987,205	111	121,987,094
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(33,892,545)	(31)	(33,892,514)
Net Income (Loss)	85,963,029	79	85,962,950
Net Change in Shareholders' Equity, value	331,305,891	79	$ 331,305,812
Net Change in Shareholders' Equity, shares			9,600,000
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
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	197,190,458		$ 197,190,458
Sale of Shares - Shares			8,000,000
Redemption of Shares - Value	(474,965,055)		$ (474,965,055)
Redemption of Shares - Shares			(18,800,000)
Net Increase (Decrease) due to Share Transactions, value	(277,774,597)		$ (277,774,597)
Net Increase (Decrease) due to Share Transactions, shares			10,800,000
Net Income (Loss)
Net Investment Income (Loss)	(1,345,297)	$ (1)	$ (1,345,296)
Net Realized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(11,243,824)	(14)	(11,243,810)
Net Change in Unrealized Gain (Loss) on United States Treasury Obligations and Currency Futures Contracts	(24,410,625)	(30)	(24,410,595)
Net Income (Loss)	(36,999,746)	(45)	(36,999,701)
Net Change in Shareholders' Equity, value	(314,774,343)	(45)	$ (314,774,298)
Net Change in Shareholders' Equity, shares			10,800,000
Balance - Value at Mar. 31, 2016	$ 818,840,473	$ 981	$ 818,839,492
Balance - Shares at Mar. 31, 2016		40	33,400,000