Summary of Significant Accounting Policies - Summary of Fair Value Estimates (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in ZEN	$ 8,408	$ 4,767	$ 4,671
Investment, Type [Extensible Enumeration]	Investment in ZEN [Member]	Investment in ZEN [Member]
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in ZEN	$ 8,408	$ 4,767
Investment, Type [Extensible Enumeration]	Investment in ZEN [Member]	Investment in ZEN [Member]
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in ZEN	$ 0	$ 0
Investment, Type [Extensible Enumeration]	Investment in ZEN [Member]	Investment in ZEN [Member]
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in ZEN	$ 0	$ 0
Investment, Type [Extensible Enumeration]	Investment in ZEN [Member]	Investment in ZEN [Member]

Fair value of investment in security owned.

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+ Details

- Definition

Indicates type of investment. Includes, but is not limited to, common stock, preferred stock, convertible security, fixed income security, government security, option purchased, warrant, loan participation and assignment, commercial paper, bankers' acceptance, certificates of deposit, short-term security, repurchase agreement, and other investment company.

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+ Details