Investment in the Funds - Partnership's Investments in and Partnership's Pro-rata Share of Results of Operations of the Funds (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
% of Partners' Capital		28.94%	99.96%
Fair Value	[1]	$ 1,492,447	$ 6,430,471
Expenses, Clearing Fees		24,277
Expenses, Professional fees		177,853
Net income (loss)		114,263	$ (135,423)	$ (1,173,481)
Cambridge Master Fund L.P. [Member]
Investment Holdings [Line Items]
% of Partners' Capital			99.96%
Fair Value			$ 6,430,471
Net income (loss)		$ (3,015,137)	2,109,033
CMF AE Capital Master Fund LLC [Member]
Investment Holdings [Line Items]
% of Partners' Capital		28.94%
Fair Value		$ 1,492,447
Net income (loss)		(1,000,434)
Investment in Funds [Member]
Investment Holdings [Line Items]
Income (Loss)		(18,034)	295,465
Expenses, Clearing Fees		12,475
Expenses, Professional fees		6,528
Net income (loss)		(37,037)	295,465
Investment in Funds [Member] | Commodity [Member] | Cambridge Master Fund L.P. [Member]
Investment Holdings [Line Items]
Income (Loss)		57,162	295,465
Expenses, Clearing Fees		1,001
Expenses, Professional fees		1,017
Net income (loss)		$ 55,144	$ 295,465
Investment Objective		Commodity Portfolio	Commodity Portfolio
Redemptions Permitted		Monthly	Monthly
Investment in Funds [Member] | Commodity [Member] | CMF AE Capital Master Fund LLC [Member]
Investment Holdings [Line Items]
Income (Loss)		$ (75,196)
Expenses, Clearing Fees		11,474
Expenses, Professional fees		5,511
Net income (loss)		$ (92,181)
Investment Objective		Commodity Portfolio
Redemptions Permitted		Monthly

[1] Defined in Note 1.