Marketable Securities (Tables)

3 Months Ended

Dec. 31, 2021

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 as well as unrealized holding gains (losses) on the short-term and long-term marketable securities as of December 31, 2021 and September 30, 2021 (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Losses		Gains		Fair Value
December 31, 2021:
Bank certificates of deposits	$	25	$	—	$	—	$	25
Corporate securities		3,703		—		—		3,703
Municipal securities		46		—		—		46
	$	3,774	$	—	$	—	$	3,774
September 30, 2021:
Bank certificates of deposits	$	30	$	—	$	—	$	30
Corporate securities		3,624		—		—		3,624
Other debt securities		25		—		—		25
	$	3,679	$	—	$	—	$	3,679

Fair Value of Marketable Securities by Contractual Maturity

The fair values of the marketable securities by contractual maturities at December 31, 2021 are presented below (in thousands):

	Fair Value
Due in one year or less	$	46
Due after one year through five years		51
Due after five years through ten years		—
Due after ten years		3,677
Total marketable securities	$	3,774