3.3.0.814 html 227 314 1 false 80 0 false 10 false false R1.htm 0001000 - Document - Document And Entity Information Sheet http://www.idt.com/role/DocumentAndEntityInformation Document And Entity Information Cover 1 false false R2.htm 1001000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS Sheet http://www.idt.com/role/CondensedConsolidatedBalanceSheets CONDENSED CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 1001501 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.idt.com/role/CondensedConsolidatedBalanceSheetsParenthetical CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 1002000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Sheet http://www.idt.com/role/CondensedConsolidatedStatementsOfOperations CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Statements 4 false false R5.htm 1003000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://www.idt.com/role/CondensedConsolidatedStatementsOfComprehensiveIncome CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Statements 5 false false R6.htm 1005000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.idt.com/role/CondensedConsolidatedStatementsOfCashFlows CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 6 false false R7.htm 2101100 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.idt.com/role/SummaryOfSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 7 false false R8.htm 2102100 - Disclosure - Net Income Per Share Sheet http://www.idt.com/role/NetIncomePerShare Net Income Per Share Notes 8 false false R9.htm 2103100 - Disclosure - Discontinued Operations Sheet http://www.idt.com/role/DiscontinuedOperations Discontinued Operations Notes 9 false false R10.htm 2106100 - Disclosure - Fair Value Measurement Sheet http://www.idt.com/role/FairValueMeasurement Fair Value Measurement Notes 10 false false R11.htm 2107100 - Disclosure - Investments Sheet http://www.idt.com/role/Investments Investments Notes 11 false false R12.htm 2108100 - Disclosure - Stock-Based Employee Compensation Sheet http://www.idt.com/role/StockBasedEmployeeCompensation Stock-Based Employee Compensation Notes 12 false false R13.htm 2109100 - Disclosure - Stockholders' Equity Sheet http://www.idt.com/role/StockholdersEquity Stockholders' Equity Notes 13 false false R14.htm 2110100 - Disclosure - Balance Sheet Detail Sheet http://www.idt.com/role/BalanceSheetDetail Balance Sheet Detail Notes 14 false false R15.htm 2111100 - Disclosure - Deferred Income on Shipments to Distributors Sheet http://www.idt.com/role/DeferredIncomeOnShipmentsToDistributors Deferred Income on Shipments to Distributors Notes 15 false false R16.htm 2112100 - Disclosure - Accumulated Other Comprehensive Income (Loss) Sheet http://www.idt.com/role/AccumulatedOtherComprehensiveIncomeLoss Accumulated Other Comprehensive Income (Loss) Notes 16 false false R17.htm 2113100 - Disclosure - Goodwill and Intangible Assets, Net Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNet Goodwill and Intangible Assets, Net Notes 17 false false R18.htm 2114100 - Disclosure - Restructuring Sheet http://www.idt.com/role/Restructuring Restructuring Notes 18 false false R19.htm 2115100 - Disclosure - Commitments and Contingencies Sheet http://www.idt.com/role/CommitmentsAndContingencies Commitments and Contingencies Notes 19 false false R20.htm 2116100 - Disclosure - Employee Benefit Plans Sheet http://www.idt.com/role/EmployeeBenefitPlans Employee Benefit Plans Notes 20 false false R21.htm 2117100 - Disclosure - Income Taxes Sheet http://www.idt.com/role/IncomeTaxes Income Taxes Notes 21 false false R22.htm 2118100 - Disclosure - Segment Information Sheet http://www.idt.com/role/SegmentInformation Segment Information Notes 22 false false R23.htm 2119100 - Disclosure - Derivative Financial Instruments Sheet http://www.idt.com/role/DerivativeFinancialInstruments Derivative Financial Instruments Notes 23 false false R24.htm 2120100 - Disclosure - Subsequent Events Sheet http://www.idt.com/role/SubsequentEvents Subsequent Events Notes 24 false false R25.htm 2201201 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.idt.com/role/SummaryOfSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.idt.com/role/SummaryOfSignificantAccountingPolicies 25 false false R26.htm 2302301 - Disclosure - Net Income Per Share (Tables) Sheet http://www.idt.com/role/NetIncomePerShareTables Net Income Per Share (Tables) Tables http://www.idt.com/role/NetIncomePerShare 26 false false R27.htm 2303301 - Disclosure - Discontinued Operations (Tables) Sheet http://www.idt.com/role/DiscontinuedOperationsTables Discontinued Operations (Tables) Tables http://www.idt.com/role/DiscontinuedOperations 27 false false R28.htm 2306301 - Disclosure - Fair Value Measurement (Tables) Sheet http://www.idt.com/role/FairValueMeasurementTables Fair Value Measurement (Tables) Tables http://www.idt.com/role/FairValueMeasurement 28 false false R29.htm 2307301 - Disclosure - Investments (Tables) Sheet http://www.idt.com/role/InvestmentsTables Investments (Tables) Tables http://www.idt.com/role/Investments 29 false false R30.htm 2308301 - Disclosure - Stock-Based Employee Compensation (Tables) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationTables Stock-Based Employee Compensation (Tables) Tables http://www.idt.com/role/StockBasedEmployeeCompensation 30 false false R31.htm 2310301 - Disclosure - Balance Sheet Detail (Tables) Sheet http://www.idt.com/role/BalanceSheetDetailTables Balance Sheet Detail (Tables) Tables http://www.idt.com/role/BalanceSheetDetail 31 false false R32.htm 2311301 - Disclosure - Deferred Income on Shipments to Distributors (Tables) Sheet http://www.idt.com/role/DeferredIncomeOnShipmentsToDistributorsTables Deferred Income on Shipments to Distributors (Tables) Tables http://www.idt.com/role/DeferredIncomeOnShipmentsToDistributors 32 false false R33.htm 2312301 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables) Sheet http://www.idt.com/role/AccumulatedOtherComprehensiveIncomeLossTables Accumulated Other Comprehensive Income (Loss) (Tables) Tables http://www.idt.com/role/AccumulatedOtherComprehensiveIncomeLoss 33 false false R34.htm 2313301 - Disclosure - Goodwill and Intangible Assets, Net (Tables) Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNetTables Goodwill and Intangible Assets, Net (Tables) Tables http://www.idt.com/role/GoodwillAndIntangibleAssetsNet 34 false false R35.htm 2314301 - Disclosure - Restructuring (Tables) Sheet http://www.idt.com/role/RestructuringTables Restructuring (Tables) Tables http://www.idt.com/role/Restructuring 35 false false R36.htm 2318301 - Disclosure - Segment Information (Tables) Sheet http://www.idt.com/role/SegmentInformationTables Segment Information (Tables) Tables http://www.idt.com/role/SegmentInformation 36 false false R37.htm 2401402 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://www.idt.com/role/SummaryOfSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) Details http://www.idt.com/role/SummaryOfSignificantAccountingPoliciesPolicies 37 false false R38.htm 2402402 - Disclosure - Net Income Per Share (Computation) (Details) Sheet http://www.idt.com/role/NetIncomePerShareComputationDetails Net Income Per Share (Computation) (Details) Details http://www.idt.com/role/NetIncomePerShareTables 38 false false R39.htm 2403402 - Disclosure - Discontinued Operations (Narrative) (Details) Sheet http://www.idt.com/role/DiscontinuedOperationsNarrativeDetails Discontinued Operations (Narrative) (Details) Details http://www.idt.com/role/DiscontinuedOperationsTables 39 false false R40.htm 2403403 - Disclosure - Discontinued Operations (Divestiture) (Details) Sheet http://www.idt.com/role/DiscontinuedOperationsDivestitureDetails Discontinued Operations (Divestiture) (Details) Details http://www.idt.com/role/DiscontinuedOperationsTables 40 false false R41.htm 2403404 - Disclosure - Discontinued Operations (Results of Operations) (Details) Sheet http://www.idt.com/role/DiscontinuedOperationsResultsOfOperationsDetails Discontinued Operations (Results of Operations) (Details) Details http://www.idt.com/role/DiscontinuedOperationsTables 41 false false R42.htm 2406402 - Disclosure - Fair Value Measurement (Levels 1-3) (Details) Sheet http://www.idt.com/role/FairValueMeasurementLevels13Details Fair Value Measurement (Levels 1-3) (Details) Details http://www.idt.com/role/FairValueMeasurementTables 42 false false R43.htm 2407402 - Disclosure - Investments (Available-for-Sale) (Details) Sheet http://www.idt.com/role/InvestmentsAvailableForSaleDetails Investments (Available-for-Sale) (Details) Details http://www.idt.com/role/InvestmentsTables 43 false false R44.htm 2407403 - Disclosure - Investments (Contractual Maturity) (Details) Sheet http://www.idt.com/role/InvestmentsContractualMaturityDetails Investments (Contractual Maturity) (Details) Details http://www.idt.com/role/InvestmentsTables 44 false false R45.htm 2407404 - Disclosure - Investments (Unrealized Loss) (Details) Sheet http://www.idt.com/role/InvestmentsUnrealizedLossDetails Investments (Unrealized Loss) (Details) Details http://www.idt.com/role/InvestmentsTables 45 false false R46.htm 2407405 - Disclosure - Investments (Cost-Method) (Details) Sheet http://www.idt.com/role/InvestmentsCostMethodDetails Investments (Cost-Method) (Details) Details http://www.idt.com/role/InvestmentsTables 46 false false R47.htm 2408402 - Disclosure - Stock-Based Employee Compensation-Options (Narrative) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationOptionsNarrativeDetails Stock-Based Employee Compensation-Options (Narrative) (Details) Details http://www.idt.com/role/StockBasedEmployeeCompensationTables 47 false false R48.htm 2408403 - Disclosure - Stock-Based Employee Compensation-Equity Instruments Other than Options (Narrative) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationEquityInstrumentsOtherThanOptionsNarrativeDetails Stock-Based Employee Compensation-Equity Instruments Other than Options (Narrative) (Details) Details 48 false false R49.htm 2408404 - Disclosure - Stock-Based Employee Compensation (Expense by Category) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationExpenseByCategoryDetails Stock-Based Employee Compensation (Expense by Category) (Details) Details http://www.idt.com/role/StockBasedEmployeeCompensationTables 49 false false R50.htm 2408405 - Disclosure - Stock-Based Employee Compensation (Stock Option Activity) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationStockOptionActivityDetails Stock-Based Employee Compensation (Stock Option Activity) (Details) Details http://www.idt.com/role/StockBasedEmployeeCompensationTables 50 false false R51.htm 2408406 - Disclosure - Stock-Based Employee Compensation (Restricted and Performance-Based Stock Unit Activity) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationRestrictedAndPerformanceBasedStockUnitActivityDetails Stock-Based Employee Compensation (Restricted and Performance-Based Stock Unit Activity) (Details) Details http://www.idt.com/role/StockBasedEmployeeCompensationTables 51 false false R52.htm 2408407 - Disclosure - Stock-Based Employee Compensation (Monte Carlo Assumptions) (Details) Sheet http://www.idt.com/role/StockBasedEmployeeCompensationMonteCarloAssumptionsDetails Stock-Based Employee Compensation (Monte Carlo Assumptions) (Details) Details http://www.idt.com/role/StockBasedEmployeeCompensationTables 52 false false R53.htm 2408408 - Disclosure - Share-Based Employee Compensation (Employee Stock Purchase Plan) (Details) Sheet http://www.idt.com/role/ShareBasedEmployeeCompensationEmployeeStockPurchasePlanDetails Share-Based Employee Compensation (Employee Stock Purchase Plan) (Details) Details 53 false false R54.htm 2409401 - Disclosure - Stockholders' Equity (Narrative) (Details) Sheet http://www.idt.com/role/StockholdersEquityNarrativeDetails Stockholders' Equity (Narrative) (Details) Details http://www.idt.com/role/StockholdersEquity 54 false false R55.htm 2410402 - Disclosure - Balance Sheet Detail (Additional Information) (Details) Sheet http://www.idt.com/role/BalanceSheetDetailAdditionalInformationDetails Balance Sheet Detail (Additional Information) (Details) Details http://www.idt.com/role/BalanceSheetDetailTables 55 false false R56.htm 2411402 - Disclosure - Deferred Income on Shipments to Distributors (Components) (Details) Sheet http://www.idt.com/role/DeferredIncomeOnShipmentsToDistributorsComponentsDetails Deferred Income on Shipments to Distributors (Components) (Details) Details http://www.idt.com/role/DeferredIncomeOnShipmentsToDistributorsTables 56 false false R57.htm 2412402 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Changes) (Details) Sheet http://www.idt.com/role/AccumulatedOtherComprehensiveIncomeLossChangesDetails Accumulated Other Comprehensive Income (Loss) (Changes) (Details) Details http://www.idt.com/role/AccumulatedOtherComprehensiveIncomeLossTables 57 false false R58.htm 2413402 - Disclosure - Goodwill and Intangible Assets, Net (Narrative) (Details) Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNetNarrativeDetails Goodwill and Intangible Assets, Net (Narrative) (Details) Details http://www.idt.com/role/GoodwillAndIntangibleAssetsNetTables 58 false false R59.htm 2413403 - Disclosure - Goodwill and Intangible Assets, Net (Goodwill by Segment) (Details) Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNetGoodwillBySegmentDetails Goodwill and Intangible Assets, Net (Goodwill by Segment) (Details) Details http://www.idt.com/role/GoodwillAndIntangibleAssetsNetTables 59 false false R60.htm 2413404 - Disclosure - Goodwill and Intangible Assets, Net (Intangible Assets) (Details) Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNetIntangibleAssetsDetails Goodwill and Intangible Assets, Net (Intangible Assets) (Details) Details http://www.idt.com/role/GoodwillAndIntangibleAssetsNetTables 60 false false R61.htm 2413405 - Disclosure - Goodwill and Intangible Assets, Net (Amortization) (Details) Sheet http://www.idt.com/role/GoodwillAndIntangibleAssetsNetAmortizationDetails Goodwill and Intangible Assets, Net (Amortization) (Details) Details http://www.idt.com/role/GoodwillAndIntangibleAssetsNetTables 61 false false R62.htm 2414402 - Disclosure - Restructuring (Provision of Charges and Liability) (Details) Sheet http://www.idt.com/role/RestructuringProvisionOfChargesAndLiabilityDetails Restructuring (Provision of Charges and Liability) (Details) Details http://www.idt.com/role/RestructuringTables 62 false false R63.htm 2414403 - Disclosure - Restructuring (Narrative) (Details) Sheet http://www.idt.com/role/RestructuringNarrativeDetails Restructuring (Narrative) (Details) Details http://www.idt.com/role/RestructuringTables 63 false false R64.htm 2415401 - Disclosure - Commitments and Contingencies (Narrative) (Details) Sheet http://www.idt.com/role/CommitmentsAndContingenciesNarrativeDetails Commitments and Contingencies (Narrative) (Details) Details http://www.idt.com/role/CommitmentsAndContingencies 64 false false R65.htm 2416401 - Disclosure - Employee Benefit Plans (Narrative) (Details) Sheet http://www.idt.com/role/EmployeeBenefitPlansNarrativeDetails Employee Benefit Plans (Narrative) (Details) Details http://www.idt.com/role/EmployeeBenefitPlans 65 false false R66.htm 2417401 - Disclosure - Income Taxes (Narrative) (Details) Sheet http://www.idt.com/role/IncomeTaxesNarrativeDetails Income Taxes (Narrative) (Details) Details http://www.idt.com/role/IncomeTaxes 66 false false R67.htm 2418402 - Disclosure - Segment Information (Narrative) (Details) Sheet http://www.idt.com/role/SegmentInformationNarrativeDetails Segment Information (Narrative) (Details) Details http://www.idt.com/role/SegmentInformationTables 67 false false R68.htm 2418403 - Disclosure - Segment Information (Income) (Details) Sheet http://www.idt.com/role/SegmentInformationIncomeDetails Segment Information (Income) (Details) Details http://www.idt.com/role/SegmentInformationTables 68 false false R69.htm 2418404 - Disclosure - Segment Information (Revenues) (Details) Sheet http://www.idt.com/role/SegmentInformationRevenuesDetails Segment Information (Revenues) (Details) Details http://www.idt.com/role/SegmentInformationTables 69 false false R70.htm 2418405 - Disclosure - Segment Information (Property Plant and Equipment) (Details) Sheet http://www.idt.com/role/SegmentInformationPropertyPlantAndEquipmentDetails Segment Information (Property Plant and Equipment) (Details) Details http://www.idt.com/role/SegmentInformationTables 70 false false R71.htm 2419401 - Disclosure - Derivative Financial Instruments (Details) Sheet http://www.idt.com/role/DerivativeFinancialInstrumentsDetails Derivative Financial Instruments (Details) Details http://www.idt.com/role/DerivativeFinancialInstruments 71 false false R72.htm 2420401 - Disclosure - Subsequent Events (Details) Sheet http://www.idt.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://www.idt.com/role/SubsequentEvents 72 false false All Reports Book All Reports In ''CONDENSED CONSOLIDATED BALANCE SHEETS'', column(s) 3, 4 are contained in other reports, so were removed by flow through suppression. In ''CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS'', column(s) 1, 2 are contained in other reports, so were removed by flow through suppression. idti-20150927.xml idti-20150927_cal.xml idti-20150927_def.xml idti-20150927_lab.xml idti-20150927_pre.xml idti-20150927.xsd true true