Consolidated Statements of Financial Condition (Unaudited) (Parenthetical)	Sep. 30, 2017 $ / shares shares	Dec. 31, 2016 $ / shares shares
Class 0 Units [Member]
Members' capital:
Capital units, issued (in units)	228,112.109	319,296.990
Capital units, outstanding (in units)	228,112.109	319,296.990
Capital units, value (in dollars per unit) | $ / shares	138.81	146.92
Class 2 Units [Member]
Members' capital:
Capital units, issued (in units)	142,107.092	154,401.114
Capital units, outstanding (in units)	142,107.092	154,401.114
Capital units, value (in dollars per unit) | $ / shares	100.61	107.43