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Investment Advisory Agreements - Additional Information (Detail)	3 Months Ended
	Dec. 31, 2021 Funds
Investment Schedule [Abstract]
Number of Hennessy funds to which company provides investment advisory services	16
Notice period for termination of agreement	60 days

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- References

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- Definition

Notice period for termination of agreement.

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- Definition

Number of open end mutual funds.

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No definition available.

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