Commodity Trading Advisors and Reference Traders (Details)	9 Months Ended
	Sep. 30, 2019
Minimum
Commodity Trading Advisors and Reference Traders
Annual percentage of allocated net assets paid as a management fee to commodity trading advisors and reference traders	0.20%
Percentage of new trading profits on allocated net assets paid as a incentive fee to commodity trading advisors and reference traders	0.00%
Maximum
Commodity Trading Advisors and Reference Traders
Annual percentage of allocated net assets paid as a management fee to commodity trading advisors and reference traders	1.00%
Percentage of new trading profits on allocated net assets paid as a incentive fee to commodity trading advisors and reference traders	20.00%