Statements of Operations - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (loss) on trading of commodity futures contracts:
Realized gain (loss) on closed futures contracts		$ 229,715	$ (2,271,270)	$ (6,916,714)
Change in unrealized gain (loss) on open futures contracts		(3,364,926)	5,217,980	2,497,914
Dividend income		27,445	10,786	2,766
Interest income	[1]	53,398	32,944	3,669
ETF transaction fees		2,450	1,750	6,650
Total income (loss)		(3,051,918)	2,992,190	(4,405,715)
Expenses
General Partner management fees (Note 3)		78,805	102,306	118,848
Professional fees		71,759	114,167	101,338
Brokerage commissions		2,209	3,451	6,117
Directors' fees and insurance		1,929	2,888	3,140
License fees		1,576	2,046	2,377
Total expenses		156,278	224,858	231,820
Expense waiver (Note 3)		(61,713)	(102,092)	(89,122)
Net expenses		94,565	122,766	142,698
Net income (loss)		$ (3,146,483)	$ 2,869,424	$ (4,548,413)
Net income (loss) per limited partnership share		$ (2.49)	$ 2.03	$ (3.97)
Net income (loss) per weighted average limited partnership share		$ (3.06)	$ 2.07	$ (3.48)
Weighted average limited partnership shares outstanding		1,027,534	1,387,568	1,305,753

[1] Interest income does not exceed paid in kind of 5%.