Concentration risk threshold percentage.

No definition available.

Name:	IDT_ConcentrationRiskThresholdPercentage
Namespace Prefix:	IDT_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fully diluted basis assuming vesting, percentage.

+ References

No definition available.

+ Details

Name:	IDT_FullyDilutedMinorityInterestOwnershipPercentageByParent
Namespace Prefix:	IDT_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Internal use software policy description.

+ References

No definition available.

+ Details

Name:	IDT_InternalUseSoftwarePolicyDescription
Namespace Prefix:	IDT_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 720
-SubTopic 35
-Name Accounting Standards Codification
-Section 55
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483385/720-35-55-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 720
-SubTopic 35
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483406/720-35-50-1

+ Details

Name:	us-gaap_AdvertisingExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of expense for amortization of capitalized computer software costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-1

+ Details

Name:	us-gaap_CapitalizedComputerSoftwareAmortization1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-1

+ Details

Name:	us-gaap_CapitalizedComputerSoftwareNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The increase (decrease) during the reporting period in the amounts payable to vendors for goods and services received and the amount of obligations and expenses incurred but not paid.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

Name:	us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-7A

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amounts payable for money transfers, money orders, and consumer payment service arrangements. Settlement liabilities include amounts payable to intermediaries for global payment transfers.

+ References

No definition available.

+ Details

Name:	us-gaap_SettlementLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_EquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=IDT_ComputerSoftwareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_FurnitureAndFixturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_SoftwareAndSoftwareDevelopmentCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RestatementAxis=srt_ScenarioPreviouslyReportedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=IDT_NetTwophoneTwoZeroIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=IDT_NationalRetailSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Description of Business and Summary of Significant Accounting Policies (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023
Property, Plant and Equipment [Line Items]
Settlement liabilities	$ 13,922	$ 12,764
Customer funds deposits	(4,814)	(9,081)	$ (21,001)
Advertising expense	20,900	19,000	17,900
Amortization expense	13,200	12,800	$ 13,200
Unamortized capital expense	$ 18,500	$ 18,600
Shares excluded from the calculation of diluted earnings per share	0	0	0
Revenue Benchmark [Member] \| Customer Concentration Risk [Member]
Property, Plant and Equipment [Line Items]
Concentration risk threshold, percentage	8.90%	10.30%	10.80%
Accounts Receivable [Member] \| Customer Concentration Risk [Member]
Property, Plant and Equipment [Line Items]
Concentration risk threshold, percentage	20.40%	22.70%
Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of long-lived assets	5 years
Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of long-lived assets	7 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of long-lived assets	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of long-lived assets	5 years
Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Internal use software policy description	The Company capitalizes the cost of internal-use software that has a useful life in excess of one year.
Previously Reported [Member]
Property, Plant and Equipment [Line Items]
Settlement liabilities		$ 8,900
Customer funds deposits		$ 1,600	$ 2,000
net2phone 2.0, Inc. [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage	94.00%
Fully diluted basis assuming vesting, percentage	90.10%
National Retail Solutions [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage	81.60%
Fully diluted basis assuming vesting, percentage	79.50%