Investments (Tables)

9 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of Short-term and Long-term Investments and Marketable Securities

The following tables summarize the Company’s short-term and long-term investments and marketable securities as of June 30, 2022 and September 30, 2021 by measurement category:

	As of June 30, 2022
	(In thousands)
	Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Classified as Cash Equivalents
Commercial notes (due within ninety days)	$	25,325	$	11	$	—	$	25,336
Classified as Held to Maturity
Commercial notes (due within one year)	$	227,057	$	21	$	(1,588)	$	225,490
Commercial notes (due within one through three years)	$	165,920	$	—	$	(6,380)	$	159,540
Certificate of deposit (due within one year)	$	50,000	$	—	$	—	$	50,000
Classified as Marketable Securities
Marketable securities	$	—	$	—	$	—	$	—
Total	$	468,302	$	32	$	(7,968)	$	460,366
	As of September 30, 2021
	(In thousands)
	Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Classified as Held to Maturity
Commercial notes (due within one year)	$	56,627	$	803	$	—	$	57,430
Commercial notes (due within one through three years)	$	195,595	$	1,151	$	(103)	$	196,643
Certificate of deposit (due within one through two years)	$	50,000	$	—	$	—	$	50,000
Classified as Marketable Securities
Marketable securities	$	127,481	$	—	$	(753)	$	126,728
Total	$	429,703	$	1,954	$	(856)	$	430,801