Management Contracts Purchased - Additional Information (Detail)	Dec. 31, 2021 USD ($) Funds	Sep. 30, 2021 USD ($)
Contracts In Progress Costs And Earnings [Line Items]
Number of mutual funds \| Funds	30
Management contracts impairment amount \| $	$ 0	$ 0

Contracts In Progress Costs And Earnings [Line Items]

No definition available.

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Period Type:	duration