XML 68 R57.htm IDEA: XBRL DOCUMENT
v3.21.1

Schedule of Equity Investments (Details) (Parenthetical) - shares | 9 Months Ended | 12 Months Ended
--- | --- | ---
Apr. 30, 2021 | Jul. 31, 2020
Common Class B [Member] | Zedge Inc [Member] |  |
Schedule of Capitalization, Equity [Line Items] |  |
Number of related party shares received | 42,282 | 42,282
Common Class B [Member] | Rafael Holdings Inc. [Member] |  |
Schedule of Capitalization, Equity [Line Items] |  |
Number of related party shares received | 28,320 | 27,806
Restricted Common Class B [Member] | Rafael Holdings Inc. [Member] |  |
Schedule of Capitalization, Equity [Line Items] |  |
Number of related party shares received | 261,894 |

X
- Definition Number of related party shares received. + References No definition available. + Details
Name: | IDT_NumberOfRelatedPartySharesReceived
Namespace Prefix: | IDT_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_ScheduleOfCapitalizationEquityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=IDT_ZedgeIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=IDT_RafaelHoldingsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=IDT_RestrictedCommonClassBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |