Marketable Securities (Tables)

9 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Fair Value of Available-for-Sale Marketable Securities by Type of Security

As of June 30, 2022 and September 30, 2021, the fair value of available-for-sale marketable securities, by type of security, was as follows:

	June 30, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
U.S. Treasury notes	$	98,389	$	—	$	(1,213	)	$	—	$	97,176
Corporate bonds		85,969		—		(2,022	)		—		83,947
Commercial paper		83,225		—		—			—		83,225
	$	267,583	$	—	$	(3,235	)	$	—	$	264,348

	September 30, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Corporate bonds	$	124,678	$	93	$	(68	)	$	—	$	124,703
Commercial paper		87,471		—		—			—		87,471
U.S. Treasury notes		83,061		3		(26	)		—		83,038
	$	295,210	$	96	$	(94	)	$	—	$	295,212