Unaudited Schedule of Investments - Treasury (Parenthetical) (USD $)	6 Months Ended													12 Months Ended
	Jun. 30, 2014 U.S. Treasury Bills, 0.035% due July 3, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.030% due July 10, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.030% due July 17, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.010% due July 24, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.025% due August 7, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.025% due August 14, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.025% due August 21, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.030% due August 28, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.035% due September 4, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.035% due September 11, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.035% due September 18, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.025% due September 25, 2014 [Member]	Jun. 30, 2014 U.S. Treasury Bills, 0.040% due October 2, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.030% due January 2, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.025% due January 9, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.010% due January 16, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.005% due January 23, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.005% due January 30, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.050% due February 6, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.075% due February 13, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.080% due February 27, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.075% due March 6, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.070% due March 13, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.065% due March 20, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.070% due March 27, 2014 [Member]	Dec. 31, 2013 U.S. Treasury Bills, 0.065% due April 3, 2014 [Member]
Schedule of Investments [Line Items]
Investment Interest Rate	0.035%	0.03%	0.03%	0.01%	0.025%	0.025%	0.025%	0.03%	0.035%	0.035%	0.035%	0.025%	0.04%	0.03%	0.025%	0.01%	0.005%	0.005%	0.05%	0.075%	0.08%	0.075%	0.07%	0.065%	0.07%	0.065%
Investment maturity date	Jul. 03, 2014	Jul. 10, 2014	Jul. 17, 2014	Jul. 24, 2014	Aug. 07, 2014	Aug. 14, 2014	Aug. 21, 2014	Aug. 28, 2014	Sep. 04, 2014	Sep. 11, 2014	Sep. 18, 2014	Sep. 25, 2014	Oct. 02, 2014	Jan. 02, 2014	Jan. 09, 2014	Jan. 16, 2014	Jan. 23, 2014	Jan. 30, 2014	Feb. 06, 2014	Feb. 13, 2014	Feb. 27, 2014	Mar. 06, 2014	Mar. 13, 2014	Mar. 20, 2014	Mar. 27, 2014	Apr. 03, 2014