Investments (Tables)

9 Months Ended

Jun. 30, 2021

Held To Maturity Securities Classified [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, 2021 and September 30, 2020 by measurement category.

Held to Maturity	As of June 30, 2021
	(In thousands)
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial notes (due within one year)	$	63,924	$	711	$	-		$	64,635
Commercial notes (due within one through three years)	$	78,376	$	1,996	$	-		$	80,372
Certificate of deposit (due within two years)	$	50,000	$	-	$	-		$	50,000
Total	$	192,300	$	2,707	$	-		$	195,007
	As of September 30, 2020
	(In thousands)
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial notes (due within one year)	$	86,890	$	1,590	$	-		$	88,480
Commercial notes (due within one through three years)	$	137,487	$	4,573	$	(79	)	$	141,981
Total	$	224,377	$	6,163	$	(79	)	$	230,461

Fair Value	As of June 30, 2021
	(In thousands)
	Cost		Realized Gains/(Losses)		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Marketable securities	$	125,000	$	1,796	$	204	$	(593	)	$	126,407
Total	$	125,000	$	1,796	$	204	$	(593	)	$	126,407
	As of September 30, 2020
	(In thousands)
	Cost		Realized Gains/(Losses)		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Marketable securities	$	85,000	$	95	$	-	$	(75	)	$	85,020
Total	$	85,000	$	95	$	-	$	(75	)	$	85,020