Financial Highlights (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Blended Strategies Portfolio [Member] | Class 0 Units [Member]
Per share operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 114.88	$ 123.17
Net gain: [Abstract]
Net investment loss (in dollars per unit)	$ (0.88)	$ (1.20)
Net gain on investments (in dollars per unit)	$ 8.47	$ 4.17
Net gain (in dollars per unit)	$ 7.59	$ 2.97
Net asset value per unit, ending balance (in dollars per unit)	$ 122.47	$ 126.14
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	6.61%	2.41%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	6.61%	2.41%
Net investment loss before Incentive Allocation (in hundredths)	(0.77%)	(0.97%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(0.77%)	(0.97%)
Total expenses before Incentive Allocation (in hundredths)	0.79%	1.27%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	0.79%	1.27%
Blended Strategies Portfolio [Member] | Class 2 Units [Member]
Per share operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 90.29	$ 98.77
Net gain: [Abstract]
Net investment loss (in dollars per unit)	$ (1.14)	$ (1.48)
Net gain on investments (in dollars per unit)	$ 6.65	$ 3.36
Net gain (in dollars per unit)	$ 5.51	$ 1.88
Net asset value per unit, ending balance (in dollars per unit)	$ 95.80	$ 100.65
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	6.10%	1.90%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	6.10%	1.90%
Net investment loss before Incentive Allocation (in hundredths)	(1.22%)	(1.50%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(1.22%)	(1.50%)
Total expenses before Incentive Allocation (in hundredths)	1.27%	1.79%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	1.27%	1.79%
Systematic Strategies Portfolio [Member] | Class 0 Units [Member]
Per share operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 73.46	$ 81.35
Net gain: [Abstract]
Net investment loss (in dollars per unit)	$ (0.65)	$ (0.92)
Net gain on investments (in dollars per unit)	$ 7.81	$ 1.89
Net gain (in dollars per unit)	$ 7.16	$ 0.97
Net asset value per unit, ending balance (in dollars per unit)	$ 80.62	$ 82.32
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	9.75%	1.19%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	9.75%	1.19%
Net investment loss before Incentive Allocation (in hundredths)	(0.88%)	(1.13%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(0.88%)	(1.13%)
Total expenses before Incentive Allocation (in hundredths)	0.90%	1.27%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	0.90%	1.27%
Systematic Strategies Portfolio [Member] | Class 2 Units [Member]
Per share operating performance [Abstract]
Net asset value per unit, beginning balance (in dollars per units)	$ 68.36	$ 77.24
Net gain: [Abstract]
Net investment loss (in dollars per unit)	$ (0.93)	$ (1.27)
Net gain on investments (in dollars per unit)	$ 7.24	$ 1.80
Net gain (in dollars per unit)	$ 6.31	$ 0.53
Net asset value per unit, ending balance (in dollars per unit)	$ 74.67	$ 77.77
Ratios to average members' capital and total return [Abstract]
Total return before Incentive Allocation (in hundredths)	9.23%	0.69%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total return after Incentive Allocation (in hundredths)	9.23%	0.69%
Net investment loss before Incentive Allocation (in hundredths)	(1.36%)	(1.64%)
Incentive Allocation (in hundredths)	0.00%	0.00%
Net investment loss after Incentive Allocation (in hundredths)	(1.36%)	(1.64%)
Total expenses before Incentive Allocation (in hundredths)	1.40%	1.78%
Incentive Allocation (in hundredths)	0.00%	0.00%
Total expenses after Incentive Allocation (in hundredths)	1.40%	1.78%