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Debt Securities (Tables) | 9 Months Ended
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Apr. 30, 2019
Debt Securities [Abstract] |
Summary of marketable debt securities |
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
Available-for-sale securities: |  |  |  |  |  |  |  |  |  |  |  |
April 30, 2019: |  |  |  |  |  |  |  |  |  |  |  |
Municipal bonds |  | $ | 301 |  |  | $ | — |  |  | $ | — |  |  | $ | 301 |
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 had 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 |  | $ | 301 |
After one year through five years |  |  | — |
After five years through ten years |  |  | — |
After ten years |  |  | — |
Total |  | $ | 301 |
Summary of available-for-sale securities, unrealized loss position |
|  | Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
April 30, 2019: |  |  |  |  |  |
Total |  | $ | — |  |  | $ | — |
July 31, 2018: |  |  |  |  |  |  |  |
U.S. Treasury notes |  | $ | 1 |  |  | $ | 1,692 |

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- Definition Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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- Definition Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities. + References No definition available. + Details
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- Definition Tabular disclosure of marketable securities. This may consist of investments in certain debt and equity securities, short-term investments and other assets. + References No definition available. + Details
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