Financial Highlights (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Class 0 Units [Member]
Per unit operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 114.03	$ 122.47	$ 127.72	$ 114.88
Net income (loss) [Abstract]
Net investment loss (in dollars per unit)	$ (0.76)	$ (0.86)	$ (1.52)	$ (1.74)
Net gain (loss) on investments (in dollars per unit)	$ 1.73	$ (0.48)	$ (11.20)	$ 7.99
Net (loss) income (in dollars per unit)	$ 0.97	$ (1.34)	$ (12.72)	$ 6.25
Net asset value per unit, ending balance (in dollars per unit)	$ 115.00	$ 121.13	$ 115.00	$ 121.13
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	0.85%	(1.09%)	(9.96%)	5.44%
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	0.85%	(1.09%)	(9.96%)	5.44%
Net investment loss before Incentive Allocation (in hundredths)	(0.66%)	(0.70%)	(1.29%)	(1.46%)
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(0.66%)	(0.70%)	(1.29%)	(1.46%)
Total expenses before Incentive Allocation (in hundredths)	0.72%	0.74%	1.39%	1.56%
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	0.72%	0.74%	1.39%	1.56%
Class 2 Units [Member]
Per unit operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 87.43	$ 95.80	$ 98.41	$ 90.29
Net income (loss) [Abstract]
Net investment loss (in dollars per unit)	$ (1.03)	$ (1.13)	$ (2.08)	$ (2.28)
Net gain (loss) on investments (in dollars per unit)	$ 1.33	$ (0.39)	$ (8.60)	$ 6.27
Net (loss) income (in dollars per unit)	$ 0.30	$ (1.52)	$ (10.68)	$ 3.99
Net asset value per unit, ending balance (in dollars per unit)	$ 87.73	$ 94.28	$ 87.73	$ 94.28
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	0.35%	(1.59%)	(10.85%)	4.42%
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	0.35%	(1.59%)	(10.85%)	4.42%
Net investment loss before Incentive Allocation (in hundredths)	(1.17%)	(1.18%)	(2.30%)	(2.42%)
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(1.17%)	(1.18%)	(2.30%)	(2.42%)
Total expenses before Incentive Allocation (in hundredths)	1.23%	1.22%	2.40%	2.52%
Incentive Allocation (in hundredths)	0.00%	0.00%	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	1.23%	1.22%	2.40%	2.52%