Supplemental Balance Sheet Information - Amortized Cost, Unrealized Holding Gains and (Losses) and Fair Value of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 7,914	$ 3,936
Unrealized Losses	(5)	(3)
Fair Value	7,909	3,933
Commercial paper and corporate bonds [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	7,914	3,936
Unrealized Losses	(5)	(3)
Fair Value	$ 7,909	$ 3,933