Investment in the Funds - Net Investment Income (Loss), Trading Results and Net Income (Loss) for the Funds (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Net Investment Income (Loss)	$ (231,852)	$ (376,822)	$ (673,344)
Total Trading Results	346,115	241,399	(500,137)
Net income (loss)	114,263	(135,423)	$ (1,173,481)
Cambridge Master Fund L.P. [Member]
Investment Holdings [Line Items]
Net Investment Income (Loss)	371,194	141,596
Total Trading Results	(3,386,331)	1,967,437
Net income (loss)	(3,015,137)	$ 2,109,033
CMF AE Capital Master Fund LLC [Member]
Investment Holdings [Line Items]
Net Investment Income (Loss)	180,229
Total Trading Results	(1,180,663)
Net income (loss)	$ (1,000,434)