Debt Securities (Tables)

9 Months Ended

Apr. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale Securities

The following is a summary of available-for-sale debt securities:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
April 30, 2022:
Certificates of deposit*	$	2,000	$	—	$	(9	)	$	1,991
U.S. Treasury bills and notes		10,964		1		(80	)		10,885
Corporate bonds		3,957		—		(452	)		3,505
Municipal bonds		6,341		—		(16	)		6,325
Total	$	23,262	$	1	$	(557	)	$	22,706
July 31, 2021:
Certificates of deposit*	$	1,200	$	3	$	—		$	1,203
U.S. Treasury bills and notes		1,669		—		(17	)		1,652
Corporate bonds		6,327		38		(33	)		6,332
Municipal bonds		4,825		—		—			4,825
Total	$	14,021	$	41	$	(50	)	$	14,012

* Each of the certificates of deposit held by the Company has a CUSIP, was purchased in the secondary market through a broker and may be sold in the secondary market.

Schedule of Contractual Maturities of Available-for-sale Debt Securities

The contractual maturities of the Company’s available-for-sale debt securities at April 30, 2022 were as follows:

	Fair Value
	(in thousands)
Within one year	$	13,868
After one year through five years		5,544
After five years through ten years		2,723
After ten years		571
Total	$	22,706

Schedule of Available-for-sale Securities, Unrealized Loss Position

The following available-for-sale debt securities were in an unrealized loss position for which other-than-temporary impairments were not recognized:

		Unrealized Losses		Fair Value
		(in thousands)
April 30, 2022:
Certificates of deposit	$	9	$	1,991
U.S. Treasury bills and notes		80		887
Corporate bonds		452		3,495
Municipal bonds		16		5,907
Total	$	557	$	12,280
July 31, 2021:
U.S. Treasury bills and notes	$	17	$	1,652
Corporate bonds		33		3,293
Total	$	50	$	4,945

Schedule of Continuous Unrealized Loss Position for 12 Months or Longer

At July 31, 2021, there were no securities in a continuous unrealized loss position for 12 months or longer. At April 30, 2022, the following available-for-sale debt securities included in the table above were in a continuous unrealized loss position for 12 months or longer:

		Unrealized Losses		Fair Value
		(in thousands)
U.S. Treasury bills and notes	$	80	$	887
Corporate bonds		257		1,713
Total	$	337	$	2,600