Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Class 0 Units [Member]
Members' capital:
Capital units, issued (in units)	548,949.091	657,725.570
Capital units, outstanding (in units)	548,949.091	657,725.570
Capital units, value (in dollars per unit)	$ 121.13	$ 114.88
Class 2 Units [Member]
Members' capital:
Capital units, issued (in units)	195,376.883	203,657.512
Capital units, outstanding (in units)	195,376.883	203,657.512
Capital units, value (in dollars per unit)	$ 94.28	$ 90.29