Investments (Tables)

12 Months Ended

Sep. 30, 2021

Held To Maturity Securities Classified [Abstract]

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

The following tables summarize the Company’s short-term, long-term investments and marketable securities as of September 30, 2021 and September 30, 2020 by measurement category.

Held to Maturity	As of September 30, 2021
	(in thousands)
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
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 two years)	$	50,000	$	-	$	-		$	50,000
Total	$	302,222	$	1,954	$	(103	)	$	304,073
	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	$	4,574	$	(79	)	$	141,982
Total	$	224,377	$	6,164	$	(79	)	$	230,462
Fair Value	As of September 30, 2021
	(in thousands)
	Cost		Realized Gains/(Losses)		Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
Marketable securities	$	125,000	$	2,481	$	135		$	(888	)	$	126,728
Total	$	125,000	$	2,481	$	135		$	(888	)	$	126,728
Fair Value	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