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Debt Securities (Details 2) - USD ($) $ in Thousands | Oct. 31, 2018 | Jul. 31, 2018
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |
Unrealized Losses | $ 3 |
Fair Value | 2,237 |
U.S. Treasury notes [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Unrealized Losses | 2 | $ 1
Fair Value | 1,695 | $ 1,692
Municipal bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Unrealized Losses | 1 |
Fair Value | $ 542 |

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- 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 + Details
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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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