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Marketable Securities (Details Textual) - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
Oct. 31, 2015 | Jul. 31, 2017 | Jul. 31, 2016 | Jul. 31, 2015
Marketable Securities (Textual) |  |  |  |
Shares received Zedge Class B common stock |  |  |  | 64,624
Amount paid for Straight Path Class B common stock received |  |  |  | $ 2.1
Proceeds from maturities and sales of available-for-sale securities |  | $ 48.0 | $ 35.0 | 24.1
Realized gains from sales of available-for-sale securities | $ 0.5 | 0.3 | 0.5 |
Realized losses from sales of available-for-sale securities |  |  |  | $ 0.1
Unrealized losses, less than twelve months or longer |  |  |  |

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- Definition Marketable Securities Textual. + References No definition available. + Details
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- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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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