Marketable Securities (Tables)

6 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Summary of Amortized Cost and Fair Value, Including Accrued Interest Receivable and Unrealized Holding Gains (Losses) on Short-term and Long-term Marketable Securities

The following is a summary of the amortized cost and the fair value, including accrued interest receivable and unrealized holding gains (losses) on the short-term and long-term marketable securities as of March 31, 2020 and September 30, 2019 (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Losses		Gains		Fair Value
March 31, 2020:
Bank certificates of deposits	$	101	$	—	$	—	$	101
Corporate securities		2,555		—		—		2,555
Other debt securities		61		—		—		61
	$	2,717	$	—	$	—	$	2,717
September 30, 2019:
U.S. Treasury securities and obligations of U.S. government agencies	$	31,863	$	(2)	$	5	$	31,866
Bank certificates of deposits		750		—		—		750
Corporate securities		4,317		—		1		4,318
Other debt securities		35		—		—		35
	$	36,965	$	(2)	$	6	$	36,969

Fair Value of Marketable Securities by Contractual Maturity

The fair values of the marketable securities by contractual maturities at March 31, 2020 are presented below (in thousands):

	Fair Value
Due in one year or less	$	162
Due after one year through five years		—
Due after five years through ten years		—
Due after ten years		2,555
Total marketable securities	$	2,717