Fair Value Measurements - Summary Categorization of Trading Company's Investments Based on Level of Inputs Utilized (Detail) - Man-AHL Diversified Trading Company L.P. [Member] - USD ($)	Sep. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	$ 120,306,331	$ 103,822,971
Total Liabilities, Fair Value Measurement	(10,018,957)	(5,155,643)
Net Fair Value, Fair Value Measurement	110,287,374	98,667,328
Futures Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	6,578,870	5,408,798
Total Liabilities, Fair Value Measurement	(2,327,610)	(1,585,982)
Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	7,792,558	8,468,234
Total Liabilities, Fair Value Measurement	(7,021,360)	(3,569,661)
Swap Agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	49,272	348,240
Total Liabilities, Fair Value Measurement	(669,987)
Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	105,885,631	89,597,699
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	6,578,870	5,408,798
Total Liabilities, Fair Value Measurement	(2,327,610)	(1,585,982)
Net Fair Value, Fair Value Measurement	4,251,260	3,822,816
Level 1 [Member] \| Futures Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	6,578,870	5,408,798
Total Liabilities, Fair Value Measurement	(2,327,610)	(1,585,982)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	113,727,461	98,414,173
Total Liabilities, Fair Value Measurement	(7,691,347)	(3,569,661)
Net Fair Value, Fair Value Measurement	106,036,114	94,844,512
Level 2 [Member] \| Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	7,792,558	8,468,234
Total Liabilities, Fair Value Measurement	(7,021,360)	(3,569,661)
Level 2 [Member] \| Swap Agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	49,272	348,240
Total Liabilities, Fair Value Measurement	(669,987)
Level 2 [Member] \| Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets, Fair Value Measurement	$ 105,885,631	$ 89,597,699