Fair Value Measurements - Additional Information (Detail) $ in Millions	3 Months Ended	9 Months Ended
Mar. 31, 2026 USD ($)	Sep. 30, 2025
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Maximum maturity period of cash and cash equivalents	90 days
Cash	$ 0.2
Custodian deposits	$ 26.3
Average maturity period of cash equivalents and marketable securities	38 days
Share Purchase Agreement [Member] \| Measurement Input, Probability of Success [Member] \| Level 3 [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
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Measurement Input	0.906
Share Purchase Agreement [Member] \| Measurement Input, Discount Rate [Member] \| Level 3 [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
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Measurement Input	0.308
Sweep Account [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Cash equivalents	$ 1.7
Maximum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Maturity period of securities		1 year

Average maturity period of cash equivalents and marketable securities.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

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