Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows from Operating Activities:
Net income (loss)	$ (4,548,413)	$ (3,971,981)	$ 4,089,602
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
(Increase) decrease in commodity futures trading account - cash and cash equivalents	1,202,800	(4,576,085)	3,466,968
Unrealized (gain) loss on open futures contracts	(2,497,914)	6,009,940	(1,996,630)
(Increase) decrease in receivable from General Partner	(22,856)	34,314	(32,077)
(Increase) decrease in dividends receivable	96	425	(249)
(Increase) decrease in directors' fees and insurance receivable	(85)	(277)	(688)
(Increase) decrease in ETF transaction fees receivable	350	(350)	0
Increase (decrease) in General Partner management fees payable	(3,142)	(7,276)	(10,280)
Increase (decrease) in professional fees payable	(5,108)	(70,453)	25,229
Increase (decrease) in brokerage commissions payable	220	(1,027)	(1,400)
Increase (decrease) in license fees payable	(170)	(372)	(790)
Net cash provided by (used in) operating activities	(5,874,222)	(2,583,142)	5,539,685
Cash Flows from Financing Activities:
Addition of partnership shares	11,863,149	4,169,264	5,962,931
Redemption of partnership shares	(9,882,640)	(11,987,259)	(25,655,241)
Net cash provided by (used in) financing activities	1,980,509	(7,817,995)	(19,692,310)
Net Increase (Decrease) in Cash and Cash Equivalents	(3,893,713)	(10,401,137)	(14,152,625)
Cash and Cash Equivalents, beginning of year	15,113,447	25,514,584	39,667,209
Cash and Cash Equivalents, end of year	$ 11,219,734	$ 15,113,447	$ 25,514,584