Fair Value Measurements - Unrealized Loss on Investments (Details) - USD ($)	Mar. 31, 2025	Sep. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value	$ 550,000
Unrealized loss position, less than 12 months, gross unrealized loss	(1,000)
Unrealized loss position, more than 12 months, fair value	0
Unrealized loss position, more than 12 months, gross unrealized loss	0
Unrealized loss position, fair value	550,000	$ 0
Unrealized loss position, gross unrealized loss	(1,000)
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value	0
Unrealized loss position, less than 12 months, gross unrealized loss	0
Unrealized loss position, more than 12 months, fair value	0
Unrealized loss position, more than 12 months, gross unrealized loss	0
Unrealized loss position, fair value	0
Unrealized loss position, gross unrealized loss	0
U.S. Government Agency Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value	295,000
Unrealized loss position, less than 12 months, gross unrealized loss	0
Unrealized loss position, more than 12 months, fair value	0
Unrealized loss position, more than 12 months, gross unrealized loss	0
Unrealized loss position, fair value	295,000
Unrealized loss position, gross unrealized loss	0
Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value	255,000
Unrealized loss position, less than 12 months, gross unrealized loss	(1,000)
Unrealized loss position, more than 12 months, fair value	0
Unrealized loss position, more than 12 months, gross unrealized loss	0
Unrealized loss position, fair value	255,000
Unrealized loss position, gross unrealized loss	(1,000)
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value	0
Unrealized loss position, less than 12 months, gross unrealized loss	0
Unrealized loss position, more than 12 months, fair value	0
Unrealized loss position, more than 12 months, gross unrealized loss	0
Unrealized loss position, fair value	0
Unrealized loss position, gross unrealized loss	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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