Financial Highlights (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Per Unit operating performance: [Abstract]
Net asset value, period start (in dollars per unit)	$ 24.39		$ 28.38		$ 26.48		$ 27.76
Interest Income (in dollars per unit)	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0.01
Expenses (in dollars per unit)	$ (0.35)		$ (0.56)		$ (0.86)		$ (1.12)
Realized/Unrealized Income (Loss) (in dollars per unit)	$ 1.14	[2]	$ (0.11)	[2]	$ (0.44)	[2]	$ 1.06	[2]
Net Income (Loss) (in dollars per unit)	$ 0.79	[3]	$ (0.67)	[3]	$ (1.30)	[3]	$ (0.05)	[3],[4]
Net asset value, period end (in dollars per unit)	$ 25.18		$ 27.71		$ 25.18		$ 27.71
Ratios to average net assets: [Abstract]
Net Investment Loss (in hundredths)	(5.70%)	[5]	(8.00%)	[5]	(7.00%)	[5]	(8.00%)	[5]
Expenses before Incentive Fees (in hundredths)	5.70%	[5]	8.00%	[5]	7.00%	[5]	8.00%	[5]
Expenses after Incentive Fees (in hundredths)	5.70%	[5]	8.00%	[5]	7.00%	[5]	8.00%	[5]
Total return before incentive fees (in hundredths)	3.20%		(2.40%)		(4.90%)		(0.20%)
Total return after incentive fees (in hundredths)	3.20%		(2.40%)		(4.90%)		(0.20%)

[1] Amounts less than $0.005 per Unit.

[2] Realized/Unrealized Income (Loss) is a balancing amount necessary to reconcile the change in net asset value per Unit with the other per Unit information.

[3] Based on change in net asset value per Unit.

[4] The decrease in the net asset value per Unit while the Partnership incurred net income for the six months ended June 30, 2013, is due to the timing of redemptions of Units throughout the period.

[5] Annualized (except for incentive fees, if applicable).