Document And Entity Information Note To Financial Statement Details Textual Note 4 - Inventories Note 5 - Property and Equipment, Net Note 6 - Intangible Assets, Net Note 7 - Investments in Joint Ventures Term loans, noncurrent portion Note 9 - Stockholders' Equity Note 10 - Net Income Per Common Share LONG-TERM LIABILITIES: Note 11 - Stock-based Compensation Note 12 - Segment and Geographic Information Note 14 - Supplemental Cash Flow Information Income Tax Disclosure [Text Block] Note 4 - Inventories - Inventories (Details) Note 5 - Property and Equipment, Net - Components of Property and Equipment, Net (Details) Note 6 - Intangible Assets, Net - Intangible Assets, Net (Details) Current liabilities Total current liabilities Note 6 - Intangible Assets, Net - Future Amortization Expense (Details) Note 7 - Investments in Joint Ventures - Condensed Balance Sheet of EXCOR and All Other Joint Ventures (Details) Note 7 - Investments in Joint Ventures - Condensed Income Statement of EXCOR and All Other Joint Ventures (Details) ntic_ForeignWithholdingTax Foreign Withholding Tax The amount of foreign withholding tax. Inside the USA to Unaffiliated Customers [Member] Inside the USA to Unaffiliated Customers. Joint Ventures in Which the Company is a Shareholder Directly and Indirectly Outside the USA [Member] Joint ventures in which the company is a shareholder directly and indirectly outside the USA [member] Note 9 - Stockholders' Equity - Cash Dividends Declared (Details) Unaffiliated Customers Outside the USA [Member] Unaffiliated customers outside the USA [member] Note 10 - Net Income Per Common Share - Reconciliation of the Earnings Per Share Computations (Details) Note 11 - Stock-based Compensation - Stock Option Activity (Details) Note 11 - Stock-based Compensation - Restricted Stock Unit Activity (Details) Note 12 - Segment and Geographic Information - Net Sales by Segment (Details) Note 12 - Segment and Geographic Information - Cost of Goods Sold by Segment (Details) Note 12 - Segment and Geographic Information - Schedule of Segment Reporting Information, by Segment (Details) Share-Based Payment Arrangement, Option, Activity [Table Text Block] Note 12 - Segment and Geographic Information - Information by Geographic Location (Details) RSU granted, weighted average grant date fair value (in dollars per share) RSU vested/settled, weighted average grant date fair value (in dollars per share) ntic_TotalFeesForServicesProvidedToJointVenturesGeographicLocation Poland Total fees for services provided to joint ventures by geographic locations. Note 12 - Segment and Geographic Information - Schedule of Geographic Distribution of Revenue (Details) RSUs cancelled (in dollars per share) Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue RSU outstanding, weighted average grant date fair value (in dollars per share) RSU outstanding, weighted average grant date fair value (in dollars per share) RSUs cancelled (in shares) Note 14 - Supplemental Cash Flow Information - Supplemental Disclosures of Cash Flow Information (Details) Notes To Financial Statements OTHER COMPREHENSIVE (LOSS) INCOME – FOREIGN CURRENCY TRANSLATION ADJUSTMENT us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber RSU outstanding, shares (in shares) RSU outstanding, shares (in shares) Notes To Financial Statements [Abstract] RSU granted, shares (in shares) RSU vested/settled, shares (in shares) ntic_EntityWideFeesForServicesProvidedToJointVenturesGeographicPercentage Poland Percentage of entity wide fees for services provided to joint ventures generated from geographic location. us-gaap_LongTermDebtCurrent Long-Term Debt, Current Maturities Other comprehensive loss us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Total equity BALANCE BALANCE Line of credit us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2 Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Employee Retention Credit [Member] Relating to Employee Retention Credit. Term loan, current portion us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Outstanding, weighted average exercise price (in dollars per share) Outstanding, weighted average exercise price (in dollars per share) Cancelled (in dollars per share) Options granted, weighted average exercise price (in dollars per share) Options exercised, weighted average exercise price (in dollars per share) Payroll and related benefits Income taxes payable Accounts payable Revolving Credit Facility [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Outstanding, shares (in shares) Outstanding, shares (in shares) ZERUST [Member] Represents ZERUST. NaturTec [Member] Represents NaturTec segment. Reconciliation of Cost of Goods Sold from Segments to Consolidated [Table Text Block] Tabular disclosure of all significant reconciling items in the reconciliation of total cost of goods sold from reportable segments to the entity's consolidated revenues. us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment Proceeds from the sale of property and equipment Credit Facility [Axis] Credit Facility [Domain] Cost of Goods Sold Type [Axis] Cost of goods sold type [axis] Other Cost of Goods Sold Type [Domain] Direct Cost of Goods Sold [Member] Direct cost of goods sold [member] Indirect Cost of Goods Sold [Member] Indirect cost of goods sold [member] us-gaap_PolicyTextBlockAbstract Accounting Policies ZERUST® Represents cost of goods sold as percentage of product sales. JOINT VENTURE OPERATIONS: Joint venture operations us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Other Countries [Member] Countries identified as "Other". us-gaap_PaymentsToAcquireIntangibleAssets Investments in patents and capitalized software costs us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of property and equipment us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements Weighted shares assumed upon exercise of stock options and settlement of restricted stock units (in shares) Accrued liabilities: WEIGHTED AVERAGE COMMON SHARES Cash paid for taxes CURRENT LIABILITIES: Total assets Total assets Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Customer Relationships [Member] Deferred income tax, net us-gaap_DeferredIncomeTaxAssetsNet Computer Software, Intangible Asset [Member] Finite-Lived Intangible Assets by Major Class [Axis] Share-Based Payment Arrangement [Text Block] Finite-Lived Intangible Assets, Major Class Name [Domain] us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders Dividend to non-controlling interest Award Type [Domain] Effective Income Tax Rate Reconciliation [Table] ntic_AssetsNoncurrentOtherThanPropertyPlantAndEquipment Total other assets Sum of the carrying amounts as of the balance sheet date of all assets, excluding property, plant, and equipment that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Net income us-gaap_NetIncomeLoss NET (LOSS) INCOME ATTRIBUTABLE TO NTIC Net income Award Type [Axis] us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization Patents and trademarks Intangible assets, net Total Standby Letters of Credit [Member] Restricted Stock Units (RSUs) [Member] Patents and trademarks NET INCOME ATTRIBUTABLE TO NON-CONTROLLING INTERESTS O 2025 Q2 Dividends [Member] Represents ordinary dividends in the second quarter of the fiscal year 2025. Share-Based Payment Arrangement, Option [Member] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Loss Contingencies [Table] us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest COMPREHENSIVE (LOSS) INCOME ATTRIBUTABLE TO NON-CONTROLLING INTERESTS Commitments and Contingencies Disclosure [Text Block] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less accumulated depreciation Total property and equipment, net PROPERTY AND EQUIPMENT, NET Property and equipment, net Goodwill us-gaap_PropertyPlantAndEquipmentGross Property, Plant and Equipment, Gross us-gaap_MachineryAndEquipmentGross Machinery and equipment us-gaap_ConstructionInProgressGross Assets in process us-gaap_Land Land us-gaap_Dividends Dividends paid to stockholders us-gaap_BuildingsAndImprovementsGross Buildings and improvements Earnings Per Share, Diluted, by Common Class, Including Two-Class Method [Table] NET INCOME us-gaap_ProfitLoss NET INCOME Net income us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest COMPREHENSIVE (LOSS) INCOME CASH FLOWS FROM INVESTING ACTIVITIES: JP Morgan Chase Bank [Member] Represents information regarding the JP Morgan Chase Bank. NET (LOSS) INCOME ATTRIBUTABLE TO NTIC PER COMMON SHARE: ntic_CBFloatingRateFloor CB Floating Rate Floor The minimum percentage for CB floating rate. Earnings Per Share [Text Block] BRAZIL us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable Income tax payable Equity in income from joint ventures NTIC’s share of equity in income from joint ventures Equity in income from joint ventures Investments in joint ventures NTIC China [Member] Represents NTIC China. Adjusted SOFR Rate Applicable Margin [Member] Represents applicable margin to Adjusted SOFR rate. INCOME TAX EXPENSE us-gaap_IncreaseDecreaseInAccruedLiabilities Accrued liabilities us-gaap_GovernmentAssistanceNonoperatingIncome Government Assistance, Nonoperating Income, Increase (Decrease) CHINA us-gaap_IncreaseDecreaseInAccountsPayable Accounts payable CZECHIA GERMANY us-gaap_OperatingExpenses Total operating expenses General and administrative expenses General and administrative expenses FINLAND Cash and cash equivalents us-gaap_InterestExpenseNonoperating INTEREST EXPENSE Interest expense UNITED KINGDOM us-gaap_AllocatedShareBasedCompensationExpense Share-Based Payment Arrangement, Expense Amendment Flag us-gaap_ComprehensiveIncomeNetOfTax COMPREHENSIVE (LOSS) INCOME ATTRIBUTABLE TO NTIC dei_CityAreaCode City Area Code us-gaap_DebtInstrumentPeriodicPayment Debt Instrument, Periodic Payment INDIA us-gaap_SharesOutstanding BALANCE (in shares) BALANCE (in shares) us-gaap_CommonStockSharesOutstanding Common Stock, Shares, Outstanding (in shares) us-gaap_PreferredStockSharesOutstanding Preferred Stock, Shares Outstanding (in shares) Current Fiscal Year End Date us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate us-gaap_DebtInstrumentInterestRateStatedPercentage Debt Instrument, Interest Rate, Stated Percentage us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other JAPAN Document Fiscal Period Focus Document Fiscal Year Focus us-gaap_IncreaseDecreaseInDeferredIncomeTaxes Deferred income taxes dei_DocumentPeriodEndDate Document Period End Date dei_EntityFileNumber Entity File Number KOREA, REPUBLIC OF dei_EntityEmergingGrowthCompany Entity Emerging Growth Company us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount dei_DocumentType Document Type dei_EntitySmallBusiness Entity Small Business dei_EntityShellCompany Entity Shell Company Document Information [Line Items] Document Information [Table] dei_EntityFilerCategory Entity Filer Category Debt Instrument [Axis] dei_EntityCurrentReportingStatus Entity Current Reporting Status Debt Instrument, Name [Domain] Variable Rate [Domain] us-gaap_IncreaseDecreaseInIncomeTaxesReceivable Income taxes Variable Rate [Axis] Stock-based compensation expense Statement of Comprehensive Income [Abstract] dei_EntityTaxIdentificationNumber Entity Tax Identification Number Entity Central Index Key dei_EntityRegistrantName Entity Registrant Name Entity [Domain] Legal Entity [Axis] dei_EntityAddressAddressLine1 Entity Address, Address Line One us-gaap_AmortizationOfIntangibleAssets Amortization of Intangible Assets ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] dei_EntityAddressCityOrTown Entity Address, City or Town ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] dei_EntityAddressPostalZipCode Entity Address, Postal Zip Code dei_EntityAddressStateOrProvince Entity Address, State or Province ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Material Terms of Trading Arrangement [Text Block] dei_EntityCommonStockSharesOutstanding Entity Common Stock, Shares Outstanding (in shares) Trading Arrangements, by Individual [Table] us-gaap_StockRepurchasedAndRetiredDuringPeriodShares Stock Repurchased and Retired During Period, Shares POLAND us-gaap_IncreaseDecreaseInInventories Inventories dei_TradingSymbol Trading Symbol Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Stock issued for employee stock purchase plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd Line of Credit Facility, Interest Rate at Period End SWEDEN dei_LocalPhoneNumber Local Phone Number us-gaap_TableTextBlock Notes Tables Stock issued for employee stock purchase plan us-gaap_GainLossOnDispositionOfAssets1 Loss on disposal of assets Vesting and settlement of restricted stock unit awards (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures (in shares) us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Vesting and settlement of restricted stock unit awards THAILAND Change in allowance for credit losses Options granted, shares (in shares) Cancelled (in shares) Line of Credit Facility, Lender [Domain] us-gaap_InventoryRawMaterialsNetOfReserves Production materials Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Line of Credit Facility [Table] Selling expenses Selling Expense Selling expenses Lender Name [Axis] us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and equity us-gaap_InventoryFinishedGoodsNetOfReserves Finished goods UNITED STATES Retained earnings Research and development expenses Research and development expenses Accumulated other comprehensive loss Debt Disclosure [Text Block] Changes in current assets and liabilities: ntic_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodIncludingCashlessExercises Options exercised, shares (in shares) Number of share options (or share units) exercised during the current period, including cashless exercises. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Operating leases, less current portion Inventory Disclosure [Text Block] Cash and Cash Equivalent [Table] Schedule of Inventory, Current [Table Text Block] Inventory, Current [Table] Current portion of operating leases Operating lease right of use assets NTIC’s dividends received from joint ventures NTIC’s dividends received from joint ventures EXCOR and All Other Joint Ventures [Member] Represents EXCOR and All Other Joint Ventures. Remainder of fiscal 2025 Fiscal 2027 Fiscal 2028 Fiscal 2029 Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Fiscal 2026 us-gaap_ShareBasedCompensation Stock-based compensation expense O 2025 Q1 Dividends [Member] Represents ordinary dividends in the first quarter of the fiscal year 2025. Net sales Net sales Amortization expense us-gaap_AdjustmentForAmortization NTIC’s share of joint ventures’ undistributed earnings OPERATING EXPENSES: Schedule of Finite-Lived Intangible Assets [Table Text Block] us-gaap_Depreciation Depreciation expense Intangible Asset, Indefinite-Lived [Table] Intangible Assets Disclosure [Text Block] Current assets Total current assets Equity [Text Block] O 2026 Q2 Dividends [Member] Represents ordinary dividends in the second quarter of 2026. Income taxes Common stock, $0.02 par value per share; authorized 15,000,000 shares; issued and outstanding 9,492,001 and 9,475,490 as of February 28, 2026 and August 31, 2025, respectively Adjustments to reconcile net income to net cash provided by operating activities: us-gaap_CommonStockSharesAuthorized Common Stock, Shares Authorized (in shares) us-gaap_CommonStockSharesIssued Common Stock, Shares, Issued (in shares) us-gaap_CommonStockParOrStatedValuePerShare Common Stock, Par or Stated Value Per Share (in dollars per share) Revision of Prior Period [Axis] Revision of Prior Period [Domain] Previously Reported [Member] Term Loan in May [Member] Represents term loan in May. Term Loan in April [Member] Represents term loan in April. Product and Service [Axis] Product and Service [Domain] Investment, Name [Domain] Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Preferred stock, no par value; authorized 10,000 shares; none issued and outstanding us-gaap_PreferredStockSharesIssued Preferred Stock, Shares Issued (in shares) Cash paid for interest Prepaid expenses Investment, Name [Axis] Cash Flow, Supplemental Disclosures [Text Block] us-gaap_PreferredStockNoParValue Preferred Stock, No Par Value (in dollars per share) Property, Plant and Equipment Disclosure [Text Block] Geographical [Axis] Geographical [Domain] Property, Plant and Equipment [Table Text Block] us-gaap_PreferredStockSharesAuthorized Preferred Stock, Shares Authorized (in shares) Inventories, net Total inventories us-gaap_ProceedsFromDividendsReceived Dividends received from joint ventures Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Reconciliation of Revenue from Segments to Consolidated [Table] Non-controlling interests Revision of Prior Period, Reclassification, Adjustment [Member] CASH FLOWS FROM OPERATING ACTIVITIES: Other income us-gaap_OtherIncome Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Statement [Line Items] us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent Accounts Receivable, Allowance for Credit Loss, Current us-gaap_NumberOfReportableSegments Number of Reportable Segments Foreign Currency Term Loan Agreement [Member] Represents a Foreign Currency Term Loan Agreement. Receivables: IDFC First Bank Limited [Member] Represents IDFC First Bank Limited. ntic_DebtInstrumentCollateralLienOnCashDeposits Debt Instrument, Collateral, Lien on Cash Deposits The size of the lien on cash deposits that is being used as collateral. ntic_DebtInstrumentRepaymentsNumberOfMonthlyInstallments Debt Instrument, Repayments, Number of Monthly Installments The number of monthly repayments required for a debt instrument. NET SALES: Acobal [Member] Represents Acobal. Natur-Tec India [Member] Represents Natur-Tec India. Additional paid-in capital AOCI Attributable to Parent [Member] Zerust OY [Member] Represents Zerust OY. ntic_IncreaseDecreaseInTradeReceivables Trade The net change during the reporting period in amount due within one year (or one business cycle) from joint ventures for the credit sale of goods and services that have been delivered or sold in the normal course of business. O 2026 Q1 Dividends [Member] Represents the 2026 Q1 dividends. Property, Plant and Equipment [Table] Segment Reporting Disclosure [Text Block] OTHER INCOME CURRENT ASSETS: Interest income INTEREST INCOME us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD CASH AND CASH EQUIVALENTS AT END OF PERIOD us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS OTHER ASSETS: us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash used in financing activities EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS: us-gaap_OperatingIncomeLoss OPERATING INCOME (LOSS) us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities Gross profit Gross profit Gross profit Gross profit Cost of goods sold Indirect cost of goods sold Deferred income tax, net us-gaap_DeferredIncomeTaxLiabilitiesNet Consolidation Items [Domain] EQUITY: Consolidation Items [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Equity Method Investment [Table] Condensed Balance Sheet [Table Text Block] Condensed Income Statement [Table Text Block] us-gaap_PaymentsOfDividendsCommonStock Dividends paid on NTIC common stock Equity Method Investments and Joint Ventures Disclosure [Text Block] Noncontrolling Interest [Member] us-gaap_ProceedsFromStockPlans Proceeds from employee stock purchase plan Retained Earnings [Member] Trade, less allowance for credit losses of $290,493 as of February 28, 2026 and $235,000 as of August 31, 2025 Amount due from customers or clients, but not joint ventures, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Additional Paid-in Capital [Member] Common Stock [Member] Fees for services provided to joint ventures Amounts due for royalties and service fees outside of the normal course of business from entities in which the reporting entity shares joint control with another party or group, due within 1 year (or 1 business cycle). Equity Components [Axis] Equity Component [Domain] ntic_FeesForServicesProvidedToJointVentures Fees for services provided to joint ventures Royalties and service fees from transactions directly with the reporting entity's joint ventures outside the normal course of business. us-gaap_LongTermDebt Long-Term Debt Stock, Class of Stock [Table] us-gaap_PaymentsToMinorityShareholders Dividends received by non-controlling interest us-gaap_LineOfCredit Long-Term Line of Credit us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest INCOME BEFORE INCOME TAX EXPENSE dei_DocumentQuarterlyReport Document Quarterly Report dei_EntityIncorporationStateCountryCode Entity Incorporation, State or Country Code Accounting Policies [Abstract] Significant Accounting Policies [Text Block] dei_DocumentTransitionReport Document Transition Report dei_EntityInteractiveDataCurrent Entity Interactive Data Current Amount, per share (in dollars per share) CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share) us-gaap_CommonStockDividendsPerShareCashPaid Common Stock, Dividends, Per Share, Cash Paid (in dollars per share) us-gaap_RepaymentsOfSecuredDebt Payments on term loans us-gaap_GovernmentAssistanceAmount Government Assistance, Income, Increase (Decrease) dei_SecurityExchangeName Security Exchange Name dei_Security12bTitle Title of 12(b) Security Equity Method Investment, Nonconsolidated Investee [Axis] Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member] Equity Method Investment, Nonconsolidated Investee [Domain] Government Assistance [Text Block] Government Assistance, Type [Axis] Government Assistance, Type [Domain] ntic_IncreaseDecreaseInFeesReceivableForServicesProvidedToJointVentures Fees for services provided to joint ventures The net change during the reporting period in amount due within one year (or one business cycle) from joint ventures for royalties and service fees outside of the normal course of business. Government Assistance [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Total joint venture operations ntic_IncomeFromJointVentureOperations Total joint venture operations Represents the amount of income from joint venture operations recognized during the period. Segments [Axis] Segments [Domain] us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Diluted (in shares) Diluted – weighted shares outstanding (in shares) us-gaap_RepaymentsOfLinesOfCredit Repayments of line of credit Repayments of Lines of Credit Proceeds from line of credit Proceeds from Lines of Credit Statement [Table] Statement of Financial Position [Abstract] Diluted (in dollars per share) Diluted net income per share: (in dollars per share) Basic (in shares) Basic – weighted shares outstanding (in shares) Patents and Trademarks [Member] Represents patents and trademarks. Basic (in dollars per share) Basic net income per share: (in dollars per share) us-gaap_ProceedsFromRepaymentsOfLinesOfCredit Proceeds from (Repayments of) Lines of Credit Statement of Cash Flows [Abstract] EXCOR [Member] Represents EXCOR. Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block] Statement of Stockholders' Equity [Abstract] Income Statement [Abstract] All Other [Member] Represents all other joint ventures. Revenue from External Customers by Geographic Areas [Table Text Block] us-gaap_ProceedsFromIssuanceOfDebt Proceeds from Issuance of Debt Accounting Standards Update and Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Text Block] ntic_DebtInstrumentCovenantsFixedChargeCoverageRatio Debt Instrument, Covenants, Fixed Charge Coverage Ratio Represents the fixed charge coverage ratio for the debt instrument under the covenant terms. Non-current liabilities Total long-term liabilities Payable date CASH FLOWS FROM FINANCING ACTIVITIES: Thereafter Amount of amortization for asset, excluding financial asset and goodwill, lacking physical substance with finite life expected to be recognized after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Dividends Declared [Table Text Block] Declaration date Record date Dividends [Axis] Dividends [Domain] Joint ventures’ equity Stockholders’ equity Class of Stock [Axis] us-gaap_LongTermDebtNoncurrent Long-Term Debt, Excluding Current Maturities Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Operating Segments [Member]