Organization - Additional Information (Detail)					9 Months Ended
Organization - Additional Information (Detail)	Sep. 30, 2018	Apr. 01, 2018	Jan. 19, 2018	Dec. 31, 2017	Sep. 30, 2018
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Percentage of monthly General Partner fee		0.1042%
Percentage of management fee		1.25%
Harbor Selling Agreement [Member] \| Class A [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ongoing selling agent fee			2.00%
Ongoing selling agent fee, monthly rate			0.1667%
Harbor Selling Agreement [Member] \| Class D [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ongoing selling agent fee			0.75%
Ongoing selling agent fee, monthly rate			0.0625%
CMF Willowbridge Master Fund L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Percentage of partnership owned	11.90%			9.30%
Morgan Stanley Wealth Management [Member] \| Class A [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ongoing selling agent fee					2.00%
Morgan Stanley Wealth Management [Member] \| Class D [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ongoing selling agent fee					0.75%

Ceres Tactical Macro L.P. 10-Q