XML 102 R87.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Income Taxes (Details Textual) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 22, 2017 | Oct. 31, 2016 | Jul. 31, 2018 | Jul. 31, 2017 | Jul. 31, 2016 | Sep. 30, 2017
Income Taxes (Textual) |  |  |  |  |  |
Federal net operating loss carryforwards |  |  | $ 153,000 |  |  |
Net operating loss carryforwards expiration date |  |  | 2018 |  |  |
Net operating losses expiration date |  |  | Jul. 31, 2038 |  |  |
Foreign net operating losses |  |  | $ 143,000 |  |  |
Foreign net operating loss, no expiration |  |  | 117,000 |  |  |
Foreign net operating loss, expiration in two to ten years |  |  | 25,000 |  |  |
Foreign net operating loss, expiration in twenty years |  |  | 1,000 |  |  |
Cumulative undistributed foreign earnings |  |  | $ 395,000 |  |  |
Tax credits to be received |  |  |  |  |  | $ 21,100
Tax credit, description |  |  | The Company may claim a tax credit each tax year for ten years beginning in 2018. The tax credit can be applied to 100% of the Company's New Jersey tax liability each year, and the unused amount of the annual credit can be carried forward. In addition, the Company may apply for a tax credit transfer certificate to sell unused tax credits to another business. The tax credits must be sold for no less than 75% of the value of the tax credits. |  |  |
(Provision for) benefit from income taxes |  | $ 16,600 | $ (2,902) | $ 2,021 | $ (4,110) |
Income tax expense on deferred tax assets |  |  |  | 16,017 | $ 3,049 |
U.S. federal statutory corporate tax rate |  |  | 26.90% |  |  |
U.S. federal statutory tax rate, thereafter |  |  | 21.00% |  |  |
Federal net operating loss carryforwards used to offset transition tax |  |  | $ 12,000 |  |  |
Decrease in deferred tax assets |  |  | 5,668 | 11,841 |  |
Gross deferred tax assets revision |  |  | 27,900 |  |  |
Minimum [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
U.S. federal statutory corporate tax rate | 21.00% |  |  |  |  |
Maximum [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
U.S. federal statutory corporate tax rate | 35.00% |  |  |  |  |
Rafael Spin-Off [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
Decrease to deferred tax assets and valuation allowance |  |  | 6,000 |  |  |
Valuation Allowance [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
(Provision for) benefit from income taxes |  |  | 3,300 |  |  |
Noncurrent receivable |  |  | 3,300 |  |  |
US Deferred Tax Assets [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
Income tax expense on deferred tax assets |  |  |  | 11,100 |  |
Elmion Netherlands B.V. [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
(Provision for) benefit from income taxes |  |  |  | $ 16,600 |  |
Net2phone [Member] |  |  |  |  |  |
Income Taxes (Textual) |  |  |  |  |  |
Net operating losses, federal |  |  | $ 77,000 |  |  |
Net operating losses expiration, description |  |  | Expire through fiscal 2027. |  |  |
Losses limited under internal revenue code |  |  | $ 7,000 |  |  |

X
- Definition The amount of deferred tax assets and valuation allowance decrease. + References No definition available. + Details
Name: | idt_DeferredTaxAssetsAndValuationAllowanceDecrease
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of deferred tax assets and valuation allowance revision decrease. + References No definition available. + Details
Name: | idt_DeferredTaxAssetsAndValuationAllowanceRevisionDecrease
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition It represents about effective income tax rate reconciliation at federal statutory income tax rate phase in rate. + References No definition available. + Details
Name: | idt_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRatePhaseInRate
Namespace Prefix: | idt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of federal net operating loss carryforwards used to offset transition tax. + References No definition available. + Details
Name: | idt_FederalNetOperatingLossCarryforwardsUsedToOffsetTransitionTax
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Foreign net operating loss carryforwards. + References No definition available. + Details
Name: | idt_ForeignNetOperatingLossCarryForwards
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Foreign net operating loss, expiration in twenty years. + References No definition available. + Details
Name: | idt_ForeignNetOperatingLossCarryForwardsExpirationTwentyYears
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Foreign net operating loss, expiration in two to ten years. + References No definition available. + Details
Name: | idt_ForeignNetOperatingLossCarryForwardsExpirationTwoToTenYears
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Foreign net operating loss carryforwards no expiration. + References No definition available. + Details
Name: | idt_ForeignNetOperatingLossCarryForwardsNoExpiration
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | idt_IncomeTaxesTextualAbstract
Namespace Prefix: | idt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net Operating Loss Carryforwards Begins To Expire. + References No definition available. + Details
Name: | idt_NetOperatingLossCarryForwardsBeginsToExpire
Namespace Prefix: | idt_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net operating loss carryforwards year of expiration. + References No definition available. + Details
Name: | idt_NetOperatingLossCarryForwardsYearOfExpiration
Namespace Prefix: | idt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Subsidiary tax federal net operating loss carryforwards. + References No definition available. + Details
Name: | idt_SubsidiaryTaxFederalNetOperatingLossCarryForwards
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total Subsidiary Tax Net Operating Loss Carry Forwards Annual Limit Amount Under Internal Revenue Code. + References No definition available. + Details
Name: | idt_TotalSubsidiaryTaxNetOperatingLossCarryForwardsAnnualLimitAmountUnderInternalRevenueCode
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Carrying amount due after one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(17)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(5)(c)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_IncomeTaxesReceivableNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Expiration date of each operating loss carryforward included in operating loss carryforward, in CCYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwardsExpirationDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition A description of the origin, nature, and characteristics of the tax credit carryforward. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_TaxCreditCarryforwardDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 740 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6487024&loc=d3e29054-158556 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(c) -URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=115928272&loc=d3e28200-109314 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 740 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6479915&loc=d3e66715-112838 + Details
Name: | us-gaap_UndistributedEarningsOfForeignSubsidiaries
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=idt_RafaelSpinOffMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=idt_UsDeferredTaxAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=idt_ElmionNetherlandsBVMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |