Debt Securities (Tables)

12 Months Ended

Jul. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of marketable debt securities

(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available-for-sale securities:
July 31, 2019
Certificates of deposit*	$	2,234	$	—	$	—		$	2,234
Municipal bonds		300		—		—			300
TOTAL	$	2,534	$	—	$	—		$	2,534
July 31, 2018
Certificates of deposit*	$	3,032	$	—	$	—		$	3,032
U.S. Treasury notes		1,693		—		(1	)		1,692
Municipal bonds		888		—		—			888
TOTAL	$	5,613	$	—	$	(1	)	$	5,612

* 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

(in thousands)	Fair Value
Within one year	$	2,534
After one year through five years		—
After five years through ten years		—
After ten years		—
TOTAL	$	2,534

Schedule of available-for-sale securities, unrealized loss position

(in thousands)	Unrealized Losses		Fair Value
July 31, 2018
U.S. Treasury notes	$	1	$	1,692