Debt Securities (Tables)

6 Months Ended

Jan. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Schedule of marketable debt securities

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
January 31, 2020:
Certificates of deposit*	$	8,750	$	—	$	—	$	8,750
July 31, 2019:
Certificates of deposit*	$	2,234	$	—	$	—	$	2,234
Municipal bonds		300		—		—		300
Total	$	2,534	$	—	$	—	$	2,534

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

Schedule of available-for-sale debt securities

	Fair Value
	(in thousands)
Within one year	$	7,550
After one year through five years		1,200
After five years through ten years		—
After ten years		—
Total	$	8,750