Marketable Securities (Tables)

6 Months Ended

Jan. 31, 2018

Marketable Securities [Abstract]

Summary of marketable securities

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Available-for-sale securities:
January 31, 2018:
Certificates of deposit*	$	24,441	$	2	$	(1	)	$	24,442
Federal Government Sponsored Enterprise notes		3,216		—		(26	)		3,190
International agency notes		399		—		(9	)		390
Mutual funds		5,425		40		—			5,465
Corporate bonds		3,332		—		(39	)		3,293
Equity		79		—		(3	)		76
U.S. Treasury notes		5,397		—		(76	)		5,321
Municipal bonds		4,029		—		(4	)		4,025
Total	$	46,318	$	42	$	(158	)	$	46,202
July 31, 2017:
Certificates of deposit*	$	29,011	$	1	$	(7	)	$	29,005
Federal Government Sponsored Enterprise notes		3,992		—		(14	)		3,978
International agency notes		291		—		—			291
Mutual funds		5,353		77		—			5,430
Corporate bonds		4,643		—		—			4,643
Equity		74		—		(26	)		48
U.S. Treasury notes		6,673		—		—			6,673
Municipal bonds		8,201		4		(1	)		8,204
Total	$	58,238	$	82	$	(48	)	$	58,272

* 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.

Summary of available-for-sale debt securities

	Fair Value
	(in thousands)
Within one year	$	25,771
After one year through five years		14,890
After five years through ten years		—
After ten years		—
Total	$	40,661

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

	Unrealized Losses		Fair Value
	(in thousands)
January 31, 2018:
Certificates of deposit	$	1	$	5,340
Federal Government Sponsored Enterprise notes		26		3,190
International agency notes		9		390
Corporate bonds		39		3,293
Equity		3		76
U.S. Treasury notes		76		5,321
Municipal bonds		4		3,067
Total	$	158	$	20,677
July 31, 2017:
Certificates of deposit	$	7	$	12,155
Federal Government Sponsored Enterprise notes		14		3,529
Equity		26		48
Municipal bonds		1		3,349
Total	$	48	$	19,081

Summary of available-for-sale securities, continuous unrealized loss position

	Unrealized Losses		Fair Value
	(in thousands)
Federal Government Sponsored Enterprise notes	$	13	$	1,810
Municipal bonds		1		348
Total	$	14	$	2,158