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Zedge Spin-Off (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Jul. 31, 2017 | Jul. 31, 2016 | Jul. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |
INCOME (LOSS) BEFORE INCOME TAXES | $ 7,620 | $ 29,468 | $ 92,203
Zedge [Member] |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |
INCOME (LOSS) BEFORE INCOME TAXES |  | 2,518 | (4)
INCOME BEFORE INCOME TAXES ATTRIBUTABLE TO IDT CORPORATION |  | $ 2,221 | $ 23

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