Financial Highlights (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Class 0 Units [Member]
Per unit operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 127.72	$ 114.88
Net income (loss) [Abstract]
Net investment loss (in dollars per unit)	$ (0.76)	$ (0.88)
Net gain (loss) on investments (in dollars per unit)	$ (12.93)	$ 8.47
Net (loss) income (in dollars per unit)	$ (13.69)	$ 7.59
Net asset value per unit, ending balance (in dollars per unit)	$ 114.03	$ 122.47
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	(10.72%)	6.61%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	(10.72%)	6.61%
Net investment loss before Incentive Allocation (in hundredths)	(0.63%)	(0.77%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(0.63%)	(0.77%)
Total expenses before Incentive Allocation (in hundredths)	0.68%	0.79%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	0.68%	0.79%
Class 2 Units [Member]
Per unit operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 98.41	$ 90.29
Net income (loss) [Abstract]
Net investment loss (in dollars per unit)	$ (1.05)	$ (1.14)
Net gain (loss) on investments (in dollars per unit)	$ (9.93)	$ 6.65
Net (loss) income (in dollars per unit)	$ (10.98)	$ 5.51
Net asset value per unit, ending balance (in dollars per unit)	$ 87.43	$ 95.80
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	(11.16%)	6.10%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	(11.16%)	6.10%
Net investment loss before Incentive Allocation (in hundredths)	(1.14%)	(1.22%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(1.14%)	(1.22%)
Total expenses before Incentive Allocation (in hundredths)	1.19%	1.27%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	1.19%	1.27%