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Marketable Securities (Details 2) - USD ($) $ in Thousands	Jul. 31, 2018	Jul. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	$ 34	$ 48
Fair Value	2,052	19,081
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses		7
Fair Value		12,155
Federal Government Sponsored Enterprise notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses		14
Fair Value		3,529
Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	33	26
Fair Value	360	48
U.S. Treasury notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	1
Fair Value	$ 1,692
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses		1
Fair Value		$ 3,349

X

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

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+ References

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