Consolidated Statements of Financial Condition (Parenthetical)	Dec. 31, 2018 $ / Unit shares	Dec. 31, 2017 $ / Unit shares
Class 0 Units [Member]
Members' capital:
Capital units, issued (in units)	125,660.811	164,393.539
Capital units, outstanding (in units)	125,660.811	164,393.539
Capital units, value (in dollars per unit) | $ / Unit	133.70	140.90
Class 2 Units [Member]
Members' capital:
Capital units, issued (in units)	116,424.562	137,512.329
Capital units, outstanding (in units)	116,424.562	137,512.329
Capital units, value (in dollars per unit) | $ / Unit	96.01	101.94