Fair Value Measurements - Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss position, less than 12 months, fair value		$ 684
Unrealized loss position, less than 12 months, gross unrealized loss		(2)
Unrealized loss position, more than 12 months, fair value		496
Unrealized loss position, more than 12 months, gross unrealized loss		(8)
Unrealized loss position, fair value	$ 0	1,180
Unrealized loss position, gross unrealized loss		(10)
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		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
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		684
Unrealized loss position, less than 12 months, gross unrealized loss		(2)
Unrealized loss position, more than 12 months, fair value		235
Unrealized loss position, more than 12 months, gross unrealized loss		(5)
Unrealized loss position, fair value		919
Unrealized loss position, gross unrealized loss		(7)
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		261
Unrealized loss position, more than 12 months, gross unrealized loss		(3)
Unrealized loss position, fair value		261
Unrealized loss position, gross unrealized loss		$ (3)

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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