Financial Highlights (Tables)

12 Months Ended

Dec. 31, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Financial Highlights for Each Class

Changes in the net asset value per Unit for the years ended December 31, 2017, 2016 and 2015 were as follows:

	2017			2017			2016			2016			2015			2015
	Class A			Class D			Class A			Class D			Class A			Class D
Net realized and unrealized gains    (losses)	$	106.31		$	112.95		$	123.94		$	130.97		$	96.20		$	100.13
Interest Income		5.76			6.13			2.52			2.68			0.34			0.36
Expenses and allocation to Special    Limited Partner		(93.86	)		(86.97	)		(74.76	)		(66.46	)		(71.72	)		(59.36	)
Increase (decrease) for the period		18.21			32.11			51.70			67.19			24.82			41.13
Net asset value per unit, beginning    of period		1,234.93			1,309.33			1,183.23			1,242.14			1,158.41			1,201.01
Net asset value per unit, end of    period	$	1,253.14		$	1,341.44		$	1,234.93		$	1,309.33		$	1,183.23		$	1,242.14

Summary of Ratios to Average Net Assets

	2017			2017			2016			2016			2015			2015
	Class A			Class D			Class A			Class D			Class A			Class D
Ratios to Average Net Assets:
Net investment income (loss) **		(6.4	)%		(6.6	)%		(6.1	)%		(4.7	)%		(6.1	)%		(5.4	)%
Allocation to Special Limited    Partner		(0.7	)%		(1.6	)%		—	%		(0.3	)%		—	%		—	%
Net investment income (loss) after    allocation to Special Limited    Partner**		(7.1	)%		(8.2	)%		(6.1	)%		(5.0	)%		(6.1	)%		(5.4	)%
Operating expenses		6.8	%		7.2	%		6.3	%		4.9	%		6.1	%		5.4	%
Allocation to Special Limited    Partner		0.7	%		1.6	%		—	%		0.3	%		—	%		—	%
Total expenses		7.5	%		8.8	%		6.3	%		5.2	%		6.1	%		5.4	%
Total return :
Total return before allocation to    Special Limited Partner		2.3	%		4.1	%		4.4	%		5.6	%		2.1	%		3.4	%
Allocation to Special Limited    Partner		(0.8	)%		(1.6	)%		—	%		(0.2	)%		—	%		—	%
Total return after allocation to    Special Limited Partner		1.5	%		2.5	%		4.4	%		5.4	%		2.1	%		3.4	%

** Interest income less total expenses (exclusive of allocation to Special Limited Partner, if applicable).