Financial Highlights - Schedule of Financial Highlights for Each Class (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class A [Member]
Class of Stock [Line Items]
Net realized and unrealized gains (losses)	$ 106.31	$ 123.94	$ 96.20
Interest Income	5.76	2.52	0.34
Expenses and allocation to Special Limited Partner	(93.86)	(74.76)	(71.72)
Increase (decrease) for the period	18.21	51.70	24.82
Net asset value per unit, beginning of period	1,234.93	1,183.23	1,158.41
Net asset value per unit, end of period	1,253.14	1,234.93	1,183.23
Class D [Member]
Class of Stock [Line Items]
Net realized and unrealized gains (losses)	112.95	130.97	100.13
Interest Income	6.13	2.68	0.36
Expenses and allocation to Special Limited Partner	(86.97)	(66.46)	(59.36)
Increase (decrease) for the period	32.11	67.19	41.13
Net asset value per unit, beginning of period	1,309.33	1,242.14	1,201.01
Net asset value per unit, end of period	$ 1,341.44	$ 1,309.33	$ 1,242.14