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Liabilities held for sale, current portion Total current liabilities * Note 2 - Summary of Significant Accounting Policies - Inventory Reserves (Details) Note 2 - Summary of Significant Accounting Policies - Estimated Useful Lives for Buildings, Improvements, Furniture, Vehicles, and Equipment (Details) Note 2 - Summary of Significant Accounting Policies - Estimated Useful Life for the Intangible Assets (Details) Note 2 - Summary of Significant Accounting Policies - Contract Liabilities (Details) Note 2 - Summary of Significant Accounting Policies - Revenues Disaggregated (Details) Note 2 - Summary of Significant Accounting Policies - Summary of Potential Common Stock Shares (Details) Note 2 - Summary of Significant Accounting Policies - Calculation of Basic and Diluted Earnings Per Share (Details) Note 2 - Summary of Significant Accounting Policies - Summary of Segment Activity (Details) Note 2 - Summary of Significant Accounting Policies - Revenue By Country (Details) Note 2 - Summary of Significant Accounting Policies - Long-lived Assets By Country (Details) Note 3 - Investments and Fair Value Measurements - Fair Value Hierarchy for Cash Equivalents and Marketable Securities (Details) Note 3 - Investments and Fair Value Measurements - Reconciliation of Changes in Fair Value (Details) Note 3 - Investments and Fair Value Measurements - Summary of Unaudited Financial Statements of Affiliate (Details) us-gaap_DerivativeSwaptionInterestRate Derivative, Swaption Interest Rate Note 3 - Investments and Fair Value Measurements - Summary of Unaudited Financial Statements of Affiliate (Details) (Parentheticals) Note 4 - Property and Equipment, Net - Property and Equipment (Details) us-gaap_OtherOperatingIncomeExpenseNet Other operating (income) expenses Note 5 - Goodwill and Other Intangible Assets - Intangible Assets (Details) us-gaap_DerivativeNumberOfInstrumentsHeld Derivative, Number of Instruments Held, Total Note 5 - Goodwill and Other Intangible Assets - Amortization (Details) Note 5 - Goodwill and Other Intangible Assets - Estimated Future Amortization (Details) Note 5 - Goodwill and Indefinite-lived Intangibles - Goodwill (Details) Note 6 - Instruments and Risk Management - Foreign Exchange Contracts Statement of Financial Position (Details) Note 7 - Notes Payable - Summary of Notes Payable (Details) Other comprehensive income (loss) Foreign currency translation adjustment Note 7 - Notes Payable - Maturity of Notes Payable (Details) us-gaap_DerivativeTermOfContract Derivative, Term of Contract Note 10 - Stockholders' Equity - Common Stock Issuances (Details) Note 10 - Stockholders' Equity - Summary of Warrants and Options Issued to Employees and Directors (Details) Note 12 - Accumulated Other Comprehensive Income Loss - Components of Accumulated Other Comprehensive Loss (Details) Note 14 - Income Taxes - Consolidated Income From Continuing Operations Before Income Taxes (Details) Note 14 - Income Taxes - Income Tax Provision (Details) Note 14 - Income Taxes - Reconciliation of the Federal Statutory Tax Rate to the Recorded Tax Provision (Benefit) (Details) Note 14 - Income Taxes - Significant Portions of Deferred Tax Assets and Liabilities (Details) Note 16 - Leases - Future Minimum Operating Lease Obligations (Details) Note 16 - Leases - Lease Cost and Other Lease Information (Details) Note 16 - Leases - Operating Leases Obligations (Details) Notes To Financial Statements Notes To Financial Statements [Abstract] Exercisable, weighted average exercise price (in dollars per share) Exercisable, weighted average remaining contract life (Year) Notes Payable - Financing notes Notes payable, current Exercisable, aggregate intrinsic value Exercisable (in shares) Balance, weighted average remaining contract life (Year) Balance, aggregate intrinsic value Options, outstanding (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Balance, weighted average exercise price (in dollars per share) Balance, weighted average exercise price (in dollars per share) Contract liabilities Current contract liabilities, January 1 Current contract liabilities, December 31 Expired, weighted average exercise price (in dollars per share) Accrued expenses Accrued Liabilities, Current, Total us-gaap_EmployeeRelatedLiabilitiesCurrent Employee-related Liabilities, Current, Total us-gaap_LessorOperatingLeaseTermOfContract Lessor, Operating Lease, Term of Contract us-gaap_LessorOperatingLeaseRenewalTerm Lessor, Operating Lease, Renewal Term Accounts payable us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Balance (in shares) Balance (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod Expired (in shares) us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent cui_GoodwillAndIntangibleAssetImpairmentIncludingDiscontinuedOperations Impairment of goodwill and other intangible assets Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill, including discontinued operations. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized us-gaap_AccountsPayableTradeCurrent Accounts Payable, Trade, Current Current Liabilities: Proceeds from sale of building, net Represents the cash inflow from sale of buildings, net. Segment assets Total assets Deferred gain on leaseback, current portion The portion of the deferred gain that was recognized in the current period. us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation Total assets of the disposal group classified as held for sale Plan Name [Axis] Plan Name [Domain] us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets Deferred tax asset cui_AssetImpairmentChargesOtherThanGoodwill Asset Impairment Charges, Other than Goodwill Amount of write-down of assets other than goodwill recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets. cui_ReclassifiedDepositsAndOtherAssetsToPrepaidAssets Reclassified Deposits and Other Assets to Prepaid Assets Represents reclassified reclassified deposits and other assets to prepaid assets. us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet Trade accounts receivables Business Description and Basis of Presentation [Text Block] Award Type [Domain] Award Date [Axis] Award Date [Domain] Award Type [Axis] us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization Accumulated amortization Finite-lived intangible asset, accumulated amortization cui_DeferredGainOnSaleOfBuilding Deferred Gain on Sale of Building Amount of gain on the sale of building that does not qualify for gain recognition as of the balance sheet date. Totals cui_StockholdersEquityAttributableToParentAdjustedBalance Balance Amount of stockholders' equity attributable to parent, after the cumulative effect adjustment of a new accounting principle applied in the period of adoption. cui_SaleOfBuildingExpenses Sale of Building, Expenses Represents the expense related to sale of building Other intangibles assets, net Finite-lived intangible asset, gross us-gaap_FiniteLivedCustomerRelationshipsGross Finite-Lived Customer Relationships, Gross January and December 2018 [Member] Represents January and December 2018. January, April, July and October 2018 [Member] Represents January, April, July and October 2018 January and July 2018 [Member] Information related to January and July 2018. Accumulated depreciation Less accumulated depreciation Commitments and Contingencies Disclosure [Text Block] Property and equipment, less accumulated depreciation of $1,441 and $1,284, respectively Property and equipment, net Goodwill Goodwill, Ending Balance Balance Balance Property, and equipment us-gaap_AccountsReceivableGross Accounts Receivable, before Allowance for Credit Loss Discontinued operations Income from operations of discontinued power and electromechanical components businesses (including gain on disposal of $14,100) us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation Income tax expense Derivative Instrument [Axis] Derivative Contract [Domain] Deposits and Other Assets [Member] Carrying value of amounts transferred to third parties for security purposes that are expected to be returned or applied towards payment in the future and Amount of assets classified as other. Company Conditions, Policy [Policy Text Block] Disclosure of accounting policy for company conditions. Discontinued operations, gain on disposal Total no. of shares (in shares) cui_StockIssuedDuringPeriodSharesPursuantToRoyaltyAgreement Number of shares issued during period for pursuant to royalty agreement. cui_StockIssuedDuringPeriodSharesApprovedBonuses Total no. of shares (in shares) Number of shares issued during period for approved bonuses. Convertible Debt [Member] us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax Pretax (loss) profit of discontinued operations related to major classes of pretax (loss) profit Grant date fair value recorded at issuance cui_StockIssuedDuringPeriodValuePursuantToRoyaltyAgreement Amount of stock issued during period for pursuant to royalty agreement. cui_StockIssuedDuringPeriodValueApprovedBonuses Grant date fair value recorded at issuance Amount of stock issued during period for approved bonuses. Company share of adjusted net loss at 20.58% Net loss of affiliate Non-cash loss on equity method investment in affiliate Equity investment in affiliate Investment in VPS - equity method Equity Method Investments us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments Loss from continuing operations before income taxes and equity in net loss of affiliate Income tax benefit Continuing operations Total income tax (benefit) Interest rate swap: us-gaap_OperatingExpenses Total operating expenses us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount Defined Contribution Plan, Employer Discretionary Contribution Amount us-gaap_RestrictedCash Restricted cash at beginning of year Restricted cash at end of year us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch Defined Contribution Plan, Employer Matching Contribution, Percent of Match Cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year us-gaap_RoyaltyExpense Royalty Expense Amendment Flag Use of Estimates, Policy [Policy Text Block] us-gaap_GainLossOnSaleOfBusiness Gain (Loss) on Disposition of Business Gain on sale of businesses New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_RestrictedInvestmentsAtFairValue Certificate of deposit - restricted investment (1) Reclassification, Policy [Policy Text Block] Current Fiscal Year End Date us-gaap_NotesReceivableNet Financing Receivable, after Allowance for Credit Loss, Total Document Fiscal Period Focus Document Fiscal Year Focus Consolidation, Policy [Policy Text Block] Document Period End Date Entity Emerging Growth Company Document Type us-gaap_AssetImpairmentCharges Asset Impairment Charges, Total Entity Small Business Entity Shell Company Document Information [Line Items] Document Information [Table] Entity Public Float Entity Filer Category Entity Current Reporting Status Entity Voluntary Filers Entity Well-known Seasoned Issuer Impairment of goodwill Goodwill, Impairment Loss Goodwill impairment Revenue, percent us-gaap_ConcentrationRiskPercentage1 Concentration Risk, Percentage Statement of Comprehensive Income [Abstract] Entity Central Index Key Depreciation and amortization Entity Registrant Name Entity [Domain] Legal Entity [Axis] Customer Concentration Risk [Member] Supplier Concentration Risk [Member] Intangible asset amortization Amortization of intangibles Geographic Concentration Risk [Member] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Entity Common Stock, Shares Outstanding (in shares) Cost of Goods and Service Benchmark [Member] us-gaap_AdvertisingExpense Advertising Expense Revenue Benchmark [Member] Accounts Receivable [Member] Trading Symbol Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] us-gaap_TableTextBlock Notes Tables us-gaap_GainLossOnSaleOfOtherAssets Loss on disposal of assets Selling, general and administrative expense Provision for (credit to) bad debt Schedule of Derivative Instruments Included in Trading Activities [Table Text Block] Stock issued and stock to be issued for compensation, royalties and services The aggregate amount of noncash, equity-based employee remuneration and noncash equity-based remunerations for services rendered. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. Deposits and other assets Noncurrent deposits and other assets. Common stock issued and issuable for royalties payable pursuant to product agreements, related party Common stock issued for royalties pursuant to product agreements, related party. Provision for (credit to) bad debt expense and returns allowances This element represents allowance for bad debt expense and returns during the period. Contingent consideration The increase (decrease) during the reporting period in contingent consideration incurred but not yet paid. Accrued investment in other intangible assets at December 31 The value of accrued investment and other intangible assets acquired in noncash investing or financing activities. Assets held for sale, noncurrent portion Total noncurrent assets * Research and development Common stock issued and to be issued for consulting services and compensation in common stock Value of stock issued in lieu of cash for consulting and compensation and accrued liabilities payable during the period. us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent Other intangible assets Power and Electromechanic Segment [Member] Related to the Power and Electro-mechanic Segment. us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwillNoncurrent Goodwill us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent Property and equipment Energy Segment [Member] Related to the Energy Segment. Interest expense Interest expense cui_CashAndCashEquivalentsInForeignAccounts Cash and Cash Equivalents in Foreign Accounts Cash and cash equivalents in foreign accounts. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Derivative Instruments and Hedging Activities Disclosure [Text Block] Subsequent Event [Member] Schedule of Inventory, Current [Table Text Block] Restricted cash Restricted Cash, Noncurrent Subsequent Event Type [Axis] Subsequent Event Type [Domain] Other intangible assets, less accumulated amortization of $11,191 and $9,601, respectively Test Products International Inc. [Member] Related to the entity Test Products International Inc. Total Identifiable other intangible assets, gross Subsequent Events [Text Block] us-gaap_OtherLaborRelatedExpenses Other Labor-related Expenses us-gaap_SalariesWagesAndOfficersCompensation Salary and Wage, Excluding Cost of Good and Service Sold, Total 2025 and thereafter 2021 Fair Value of Financial Instruments, Policy [Policy Text Block] 2022 2023 2024 Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Segment Reporting, Policy [Policy Text Block] 2020 SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Foreign Currency Transactions and Translations Policy [Policy Text Block] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] Finite-lived intangible assets (Year) Finite-Lived Intangible Asset, Useful Life Earnings Per Share, Policy [Policy Text Block] Note receivable Financing Receivable, after Allowance for Credit Loss, Noncurrent, Total Revenues from external customers us-gaap_Revenues Operating expenses: Discontinued Operations, Policy [Policy Text Block] Income Tax, Policy [Policy Text Block] Royalty Agreement [Member] Related to a royalty agreement. cui_AccruedExpensesWorkingCapitalAdjustment Accrued Expenses, Working Capital Adjustment The amount of accrued expenses classified as working capital adjustment. cui_DisposalGroupIncludingDiscontinuedOperationGoodwillAndIntangibleAssetImpairment Impairment of goodwill and intangible assets Amount of goodwill and intangible asset impairment attributable to disposal group, including, but not limited to, discontinued operation. cui_AnnualSalaryYearTwo Annual Salary, Year Two The amount of annual salary to be paid in the second year. cui_AnnualSalaryYearOne Annual Salary, Year One The amount of annual salary to be paid in the first year. November Financing Note [Member] Related to the November financing note. July Financing Note [Member] cui_EmploymentAgreementAnnualLifeInsurancePremium Employment Agreement, Annual Life Insurance Premium The amount of annual life insurance premium paid in an employment agreement. cui_EmploymentAgreementStockOptionsGrantsSubjectToApproval Employment Agreement, Stock Options Grants Subject to Approval The number of stock option grants subject to approval in an employment agreement. us-gaap_SharesIssuedPricePerShare Shares Issued, Price Per Share cui_EmploymentAgreementsMaximumPercentOfSalaryForPerformance Employment Agreements, Maximum Percent of Salary for Performance The maximum percent of salary to be paid for performance in an employment agreement. cui_AnnualSalaryYearThree Annual Salary, Year Three The amount of annual salary to be paid in the third year. Daniel N. Ford [Member] Related to Daniel N. Ford. us-gaap_AssetsCurrent Total current assets William J. Clough [Member] Related to William J. Clough. cui_EmploymentAgreementSeveranceTermOfMedicalCoverage Employment Agreement, Severance, Term of Medical Coverage The term of medical coverage that will occur upon the severance of an employment agreement. Share-based Payment Arrangement [Policy Text Block] cui_EmploymentAgreementSeveranceRatioOfAnnualBaseSalary Employment Agreement, Severance, Ratio of Annual Base Salary The ratio of annual base salary to be paid in the result of severance from an employment agreement. Stockholders' Equity Note Disclosure [Text Block] Included in Prepaid Expense [Member] Amount included in prepaid expense. Amortized From Prepaid Expense [Member] Amounts amortized from prepaid expense. cui_BonusAndRoyaltyAccrued Bonus and Royalty Accrued The amount of bonus and royalty accrued. James F. O'Neil III [Member] Related to James F. O'Neil the 3rd. January, April, July, and October 2019 [Member] Related to issuances. May 2019 [Member] Related to May 2019. cui_SaleOfEquityRegistrationMaximumValue Sale of Equity, Registration, Maximum Value The maximum value of equity sales available in a registration. Included in Accrued Liabilities [Member] Amounts included in accrued liabilities. cui_OperatingLeaseRightofuseAssetReclassifiedToAssetsHeldForSale Operating Lease, Right-of-Use Asset, Reclassified to Assets Held for Sale The amount of right of use assets for operating leases reclassified to assets held for sale during the period. Energy Transfer [Member] Related to energy transfer. us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill Impairment of Intangible Assets (Excluding Goodwill), Total Compensation Related Costs, Policy [Policy Text Block] Assets held for sale, current portion Total current assets * Advertising Cost [Policy Text Block] cui_DepreciationAndAmortizationContinuingOperations Depreciation and Amortization, Continuing Operations Amount of deprecation and amortization expense attributable to property, plant and equipment and intangible assets of continuing operations. Note receivable, current portion Represents the current portion of note receivables. Impairment of deposits and other assets The amount of impairment of deposits and other assets during the period. us-gaap_DisposalGroupIncludingDiscontinuedOperationInventoryCurrent Inventories Investment in Convertible Note Receivable [Member] Represents information about investment in convertible note receivable. us-gaap_DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent Prepaid expenses and other current assets Accrued Expenses [Policy Text Block] Disclosure of the accounting policy for accrued expenses. us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount James McKenzie, Related Party [Member] Represents information about James McKenzie, related party. Revenue from Contract with Customer [Policy Text Block] Three Employees [Member] Represents information a bout three employees. Derivative Liabilities [Policy Text Block] Disclosure of accounting policy for derivative liabilities for the reporting period. us-gaap_DeferredTaxAssetsValuationAllowance Deferred Tax Assets, Valuation Allowance, Total Valuation allowance Operating loss cui_EquityMethodInvestmentSummarizedFinancialInformationOperatingIncomeLoss The amount of operating income (loss) reported by an equity method investment of the entity. cui_NoteReceivableInterestRate Note Receivable Interest Rate The interest rate on a certain note receivable. Schedule of Inventory Valuation Reserve [Table Text Block] Tabular disclosure of inventory valuation reserve. us-gaap_DeferredTaxAssetsNet Deferred tax assets after valuation allowance Common stock issued for compensation, services and royalty payments Value of shares (or other type of equity) issued during the period pursuant to royalty agreement and share-based compensation. Common stock issued for compensation, services and royalty payments (in shares) Number of shares (or other type of equity) issued during the period pursuant to royalty agreement and share-based compensation. Contract assets us-gaap_DeferredTaxAssetsLiabilitiesNet Deferred Tax Assets, Net, Total Net deferred tax asset Schedule of Useful Lives for Property Plant Equipment [Table Text Block] Tabular disclosure of useful lives for property plant and equipment. Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Two Customers [Member] Related to two distinct customers. Schedule of Estimated Useful Life [Table Text Block] Tabular disclosure of finite-lived and indefinite-lived intangible assets during the period. Charge to costs and expenses cui_ProvisionForInventoryReserve Represent the amount of provision for inventory reserve. Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Other Long-lived Assets us-gaap_NoncurrentAssets Customer List - Orbital [Member] Related to the Orbital customer list. Goodwill and Intangible Assets, Policy [Policy Text Block] Three Customers [Member] Related to three distinct customers. Trade name - Orbital [Member] Related to Orbital trade names. us-gaap_DeferredIncomeTaxLiabilities Total deferred tax liabilities Inventories Total inventories Work-in-process Revenues Revenues Revenue, amount Raw materials us-gaap_InventoryValuationReserves Inventory reserves Inventory reserves Finished goods us-gaap_AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1 Accumulated Depreciation, Depletion and Amortization, Sale or Disposal of Property, Plant and Equipment Property, plant and equipment, asset Technology -Based Asset - Software [Member] Related to the technology based asset, software. Technology - Based Asset - Know How [Member] Related to the technology based asset, know how. Power and Electromechanical Segment [Member] Related to the Power and Electro-mechanical company segment. cui_BonusAccruedAndExpensed Bonus and Royalty Accrued and Expensed Represents the amount of bonus and royalty accrued and expensed. All Others [Member] Related to all other countries. Inventory and accounts receivable reserves Disclosure of Shares Issued as Share-based Compensation and Royalty Payments [Table Text Block] Tabular disclosure of shares issued as share-based compensation and royalty payments. us-gaap_PropertyPlantAndEquipmentDisposals Property, Plant and Equipment, Disposals Estimated useful life (Year) cui_AmortizationOfDebtReceivableDiscountPremium Amortization of note receivable discount The amount of amortization of debt receivable discount (premium). Operating Lease Obligations [Member] Related to operating lease obligations. CUI Canada [Member] Related to the intangible assets in CUI Canada. Schedule of Segment Reporting Information, by Segment [Table Text Block] us-gaap_NotesAndLoansReceivableNetCurrent Financing Receivable, after Allowance for Credit Loss, Current, Total Trade accounts receivable, allowance Accounts Receivable, Allowance for Credit Loss, Current us-gaap_NumberOfOperatingSegments Number of Operating Segments Furniture and Fixtures [Member] Trade accounts receivable, net of allowance of $47 and $17, respectively us-gaap_NumberOfReportableSegments Number of Reportable Segments CUI Global Inc. [Member] Related to the entity CUI Global Inc. Building and Building Improvements [Member] Product Certification [Member] Related to the finite lived intangible asset product certification. cui_ConversionOfNotesReceivableToPreferredStock Conversion of Notes Receivable to Preferred Stock The value of notes receivable converted to preferred stock in a noncash transaction. Building [Member] Land [Member] Leasehold Improvements [Member] Property, Plant and Equipment, Policy [Policy Text Block] Multi-currency Variable Rate Overdraft Facility [Member] Related to the multi-currency variable rate overdraft facility. Wells Fargo Bank N.A [Member] Related to the entity Wells Fargo Bank. Other income (expense) Property, Plant and Equipment, Type [Axis] International Electronic Devices, Inc. [Member] Related to the entity International Electronic Devices Inc. Property, Plant and Equipment, Type [Domain] Net operating loss carryforwards Chief Executive Officer [Member] cui_AccruedRoyaltyAndLicenseFeesCurrent Accrued Royalty and License Fees, Current Carrying value as of the balance sheet date of obligations incurred through that date and payable for royalty and license fees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Current Assets: CUI Japan [Member] Related to CUI Japan. us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash, cash equivalents and restricted cash at beginning of year CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF YEAR Inventory, Policy [Policy Text Block] Office and Warehouse Space in Houston [Member] Related to the office and and warehouse space in Houston. Assets: 2008 Equity Incentive Plan [Member] Related to the 2008 Equity Incentive Plan. us-gaap_InvestmentIncomeInterest Investment Income, Interest Incentive Stock Options [Member] Related to Incentive Stock Option awards. Effect of exchange rate changes on cash Cash Less Warrant [Member] Related to the issuance of cash less warrant. us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net increase (decrease) in cash, cash equivalents and restricted cash Deferred tax assets: Over-Allotment Option [Member] us-gaap_NetCashProvidedByUsedInFinancingActivities NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES Sale of Stock [Axis] 2009 Equity Incentive Plan (Executive) [Member] Related to the 2009 Equity Incentive Plan (Executive). Sale of Stock [Domain] Loss from operations us-gaap_OperatingIncomeLoss Continuing loss from operations us-gaap_NetCashProvidedByUsedInOperatingActivities Net Cash Provided by (Used in) Operating Activities, Total NET CASH USED IN OPERATING ACTIVITIES Four Employee [Member] Related to four employees. us-gaap_NetCashProvidedByUsedInInvestingActivities NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES us-gaap_DeferredTaxLiabilities Net deferred tax (liability) us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets Intangible assets us-gaap_SaleLeasebackTransactionRentExpense Sale Leaseback Transaction, Rent Expense Cost of revenues us-gaap_GrossProfit Gross profit us-gaap_SaleLeasebackTransactionMonthlyRentalPayments Sale Leaseback Transaction, Monthly Rental Payments Three Employee [Member] Related to three employees. Derivatives, Policy [Policy Text Block] us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations Cash Provided by (Used in) Operating Activities, Discontinued Operations us-gaap_SaleLeasebackTransactionCumulativeGainRecognized1 Sale Leaseback Transaction, Cumulative Gain Recognized us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations Cash Provided by (Used in) Investing Activities, Discontinued Operations Deferred gain on leaseback, less current portion Inventory reserve Consultants [Member] Related to consultants. Employee [Member] Related to a employee. Investment, Policy [Policy Text Block] us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment Property, plant and equipment, liability Deferred tax liabilities Proceeds from sales of common stock, net of offering costs Proceeds from Issuance or Sale of Equity, Total us-gaap_PaymentsForRepurchaseOfCommonStock Cash payments for repurchases of common stock Scenario [Domain] Forecast [Member] us-gaap_ProceedsFromIssuanceOfCommonStock Proceeds from Issuance of Common Stock Title of Individual [Domain] State and local Title of Individual [Axis] us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit State and local Scenario [Axis] Foreign us-gaap_DeferredForeignIncomeTaxExpenseBenefit Foreign Federal us-gaap_DeferredFederalIncomeTaxExpenseBenefit Federal Deferred: Current: us-gaap_CurrentIncomeTaxExpenseBenefit Total current provision Foreign operations Continuing operations us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Loss from continuing operations before taxes U.S. operations us-gaap_PaymentsForDerivativeInstrumentFinancingActivities Payments for Derivative Instrument, Financing Activities Payment to closeout derivative liability Comprehensive Income (Loss) Note [Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Timing of Transfer of Good or Service [Domain] State and Local Jurisdiction [Member] Transferred at Point in Time [Member] Transferred over Time [Member] Income Tax Authority [Axis] Income Tax Authority [Domain] Disaggregation of Revenue [Table Text Block] Domestic Tax Authority [Member] Timing of Transfer of Good or Service [Axis] Foreign Tax Authority [Member] us-gaap_RepaymentsOfRelatedPartyDebt Payments on contingent consideration us-gaap_RepaymentsOfOtherLongTermDebt Payments on mortgage note payable Cash and Cash Equivalents, Policy [Policy Text Block] Receivable [Policy Text Block] Accounting Policies [Abstract] Significant Accounting Policies [Text Block] us-gaap_OpenTaxYear Open Tax Year Concentration Risk Disclosure [Text Block] us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption Cumulative effect of accounting change Receivable Type [Axis] Receivable [Domain] Power and Electromechanical Business [Member] Represents information related to the Power and Electromechanical business. Other income and expense Amount of non major other income (expense) attributable to disposal group, including, but not limited to, discontinued operation. Electromechanical Subsegment [Member] Information related to the electromechanical sub-segment. Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Provision for bad debt Amount of credit (provision) for bad debt attributable to disposal group, including, but not limited to, discontinued operation. cui_DisposalGroupIncludingDiscontinuedOperationResearchAndDevelopmentExpense Research and development Amount of research and development expense attributable to disposal group, including, but not limited to, discontinued operation. Pretax gain on sale of certain power and electromechanical businesses Amount before tax of gain (loss) on sale of components not previously recognized resulting from the disposal of a discontinued operation. cui_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilityCurrent Operating lease obligations - current portion Amount classified as operating lease liability attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer. cui_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseRightOfUseAsset Right of use assets - Operating leases Amount classified as operating lease right of use asset attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer. cui_DisposalGroupIncludingDiscontinuedOperationDepositsAndOtherAssetsNoncurrent Deposits and other assets Amount classified as deposits and other assets attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer. cui_DisposalGroupIncludingDiscontinuedOperationNotesPayableRelatedPartiesNoncurrent Long term note payable, related party Amount classified as non current notes payable related party attributable to disposal group held for sale or disposed of, expected to be disposed of beyond one year or the normal operating cycle, if longer. 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Revenue from External Customers by Geographic Areas [Table Text Block] Financing Note [Member] Represents information related to financing note. Long-lived Assets by Geographic Areas [Table Text Block] Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Intangible Assets and Goodwill [Table Text Block] Costain Oil, Gas & Process Ltd [Member] Information related to the Costain Oil, Gas & Process Ltd. S & B Engineers [Member] Information related to the S & B Engineers. Convertible note receivable Investment in Convertible Note Receivable, Noncurrent Represents the noncurrent portion of investment in convertible note receivable. 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Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Currency translation adjustments Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] cui_IncreaseDecreaseInRefundLiability Refund liabilities The amount of increase (decrease) in refund liability during the period. Two Employees [Member] Represents 2 employees. January, February and June 2017 [Member] Represents January, February and June 2017. Summary of Warrants and Options Issued [Table Text Block] Tabular disclosure of warrants and options issued. January and December 2017 [Member] Represents January and December 2017. cui_PercentageOfRevenueFromGoodsAndServices Percentage of Revenue From Goods and Services The percentage of revenue derived from goods and services. Various Third-party Shareholders [Member] Represents various third-party shareholders. January, April, August and October 2017 [Member] Represents January, April, August and October 2017. October 2017 [Member] Represents October 2017. Employee Stock Options And Warrants [Member] Related to the employee stock options and warrants. January and February 2017 [Member] Represents January and February 2017. May 2017 [Member] Represents May 2017. Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] National Grid [Member] The entity National Grid. Scotia Gas Networks plc [Member] The entity Scotia Gas Networks plc. Ownership Percentage Equity Method Investment, Ownership Percentage cui_WorkingCapital Working Capital The capital of a business that is used in its day-to-day trading operations, calculated as the current assets minus the current liabilities. cui_NoncashRoyaltiesNet Non-cash royalties, net (see Note 2 - Investment and Note Receivable) The amount of non-cash royalties, net. 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Lease Arrangement, Type [Domain] us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other current assets cui_ChangeInExcessOfBonusOrSalary Change in Excess of Bonus or Salary Represents the value of change in excess of bonus or salary. Weighted-average discount rate - operating leases Operating lease cost cui_CashBonus Cash Bonus It represents the value of cash bonus. Short-term lease cost Right-of-use assets obtained in exchange for new operating lease obligations us-gaap_IncreaseDecreaseInDepositsOutstanding Deposits and other assets Non-cash item for January 1, 2019 adoption of ASC 842 - establishment of right-of-use assets and offsetting lease obligations Weighted-average remaining lease term - operating leases (in years) (Year) us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Interim Period, Costs Not Allocable [Domain] Permanent tax differences Income tax rate reconciliation at permanent item income tax. 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Variable Rate [Axis] us-gaap_IncreaseDecreaseInAccountsReceivable Trade accounts receivable Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] us-gaap_TreasuryStockValueAcquiredCostMethod Common stock purchased as treasury shares us-gaap_TreasuryStockValue Treasury stock at cost; 353,063 shares held at December 31, 2019 and 0 shares held at December 31, 2018 us-gaap_IncreaseDecreaseInInventories Inventories Common stock issued for exercises of options (in shares) us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Common stock issued for exercises of options Related Party [Axis] Related Party [Domain] Total no. of shares (in shares) us-gaap_LineOfCreditFacilityExpirationPeriod Line of Credit Facility, Expiration Period Grant date fair value recorded at issuance Shares Issued, Value, Share-based Payment Arrangement, before Forfeiture us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Line of Credit Facility, Lender [Domain] cui_ContractWithCustomerLiabilityIncreaseDecreaseFromTranslation Translation Represents the increase (decrease) during the period in the liability from contracts with customers attributable to translation. Issuance of common stock (in shares) Stock Issued During Period, Shares, New Issues Lender Name [Axis] us-gaap_CashFDICInsuredAmount Cash, FDIC Insured Amount us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders' equity us-gaap_CashUninsuredAmount Cash, Uninsured Amount UNITED STATES Issuance of common stock (Increase) decrease in operating assets: us-gaap_IncreaseDecreaseInContractWithCustomerAsset Contract assets Accumulated deficit Retained Earnings (Accumulated Deficit), Ending Balance Accumulated other comprehensive loss Accumulated other comprehensive loss Money Market Funds [Member] Debt Disclosure [Text Block] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Operating lease obligations, less current portion Total operating lease obligations Operating lease obligations - current portion us-gaap_ForeignCurrencyTransactionGainLossUnrealized Non-cash unrealized foreign currency (gain) loss Right of use assets - Operating leases Operating Lease, Right-of-Use Asset us-gaap_FinanceLeasePrincipalPayments Payments on financing lease obligations us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Interest portion us-gaap_DeferredIncomeTaxExpenseBenefit Total deferred (benefit) us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree 2022 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour 2023 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive 2024 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive Thereafter us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths 2020 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo 2021 Foreign currency translation adjustment us-gaap_ShareBasedCompensation Share-based Payment Arrangement, Noncash Expense, Total Lessee, Operating Lease, Liability, Maturity [Table Text Block] Bank of America [Member] Information pertaining to Bank of America. VPS [Member] Information pertaining to Virtual Power Systems. us-gaap_AssetsFairValueDisclosure Total assets Depreciation Depreciation and amortization (1) us-gaap_DepreciationAndAmortizationDiscontinuedOperations Depreciation and Amortization, Discontinued Operations us-gaap_CashAndCashEquivalentsFairValueDisclosure Money market securities us-gaap_UnrealizedGainLossOnDerivatives Unrealized gain on derivative liability Note payable, related party assumed by buyer of electromechanical business as partial consideration for purchase of business Treasury stock, shares (in shares) Common stock, par value $0.001; 325,000,000 shares authorized; 28,383,373 shares issued and outstanding at December 31, 2019 and 28,552,886 shares issued and outstanding at December 31, 2018 Adjustments to reconcile net loss to net cash used in operating activities: Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Asia [Member] Statistical Measurement [Domain] us-gaap_OperatingLeasePayments Operating cash flows used in operating leases SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES: Maximum [Member] Minimum [Member] Statistical Measurement [Axis] Investment, Name [Domain] us-gaap_OperatingLeasesRentExpenseNet Operating Leases, Rent Expense, Net, Total Preferred stock, par value $0.001; 10,000,000 shares authorized; no shares issued at December 31, 2019 or December 31, 2018 Preferred stock, issued (in shares) North America [Member] Interest paid, net of capitalized interest Investment, Name [Axis] Income taxes paid Geographical [Axis] Property, Plant and Equipment Disclosure [Text Block] Geographical [Domain] Property, Plant and Equipment [Table Text Block] Preferred stock, authorized (in shares) Europe [Member] Preferred stock, par value (in dollars per share) Fair Value, Inputs, Level 3 [Member] Lessee, Operating Lease, Disclosure [Table Text Block] Fair Value Hierarchy and NAV [Domain] Customer [Axis] Customer [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value Hierarchy and NAV [Axis] CASH FLOWS FROM OPERATING ACTIVITIES: Statement [Line Items] Additional paid-in capital Orbital UK Reporting Unit [Member] Represents information about Orbital-UK Reporting Unit. AOCI Attributable to Parent [Member] Stockholders' Equity: us-gaap_NotesReceivableFairValueDisclosure Notes Receivable, Fair Value Disclosure Fair Value Disclosures [Text Block] Net loss us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss Revenues us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue us-gaap_Liabilities Total liabilities Commitments and contingencies Contract additions, net Stockholders' equity us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquity Total liabilities and stockholders' equity us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity us-gaap_ContractWithCustomerLiabilityRevenueRecognized Revenue recognized us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation Total liabilities Prepaid expenses and other current assets us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities Equity Method Investment, Summarized Financial Information, Liabilities, Total Counterparty Name [Axis] Current liabilities us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities Counterparty Name [Domain] Accounting Standards Update 2014-09 [Member] Non-current liabilities us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities Current assets us-gaap_EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets Non-current assets us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets Total Assets us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets Equity Method Investment, Summarized Financial Information, Assets, Total us-gaap_ContractWithCustomerLiability Total contract liabilities, January 1 Contract liabilities, December 31 Accounting Standards Update 2016-02 [Member] Consolidated Entities [Axis] Consolidated Entities [Domain] Type of Adoption [Domain] us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent Employee-related Liabilities, Total Adjustments for New Accounting Pronouncements [Axis] us-gaap_WorkersCompensationLiabilityCurrentAndNoncurrent Workers' Compensation Liability Disposal Group Classification [Axis] Disposal Group Classification [Domain] Equity Method Investments [Table Text Block] Retained Earnings [Member] Treasury Stock [Member] Additional Paid-in Capital [Member] Equity Components [Axis] Equity Component [Domain] us-gaap_LongTermDebt Total Ending balance us-gaap_NotesPayable Vehicles [Member] Equipment [Member] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Selling, General and Administrative Expenses [Member] Entity Interactive Data Current cui_StockCompensationExpenseRelatedToRoyaltiesAndStockBonusesAccruedButNotIssued Stock Compensation Expense Related to Royalties and Stock Bonuses Accrued But Not Issued Represents the amount of stock compensation during the period related to royalties and a stock bonus, which were earned and included in equity but not issued and outstanding at the end of the period. 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Other Segments [Member] us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities Other long-term liabilities us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent Accounts payable us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent Accrued expenses Statement [Table] us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter Thereafter us-gaap_OperatingLeasesFutureMinimumPaymentsDue Total us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense Interest expense us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears 2022 us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization Depreciation and amortization us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears 2023 us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense Selling, general and administrative expense us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue Revenues us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears 2020 us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears 2021 us-gaap_DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold Cost of revenues us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration Disposal Group, Including Discontinued Operation, Consideration Income Statement [Abstract] us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent 2019 Disposal Groups, Including Discontinued Operations [Table Text Block] us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree 2022 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour 2023 Disposal Group Name [Axis] us-gaap_RestructuringReserve Restructuring Reserve, Ending Balance us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive 2024 Disposal Group Name [Domain] us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive Thereafter us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths 2020 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo 2021 us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification Operating lease liabilities Represents increase (decrease) in operating lease liability. cui_IncreaseDecreaseInOperatingLeaseRightOfUseAsset Right of use assets - Operating leases Represents increase (decrease) in right of use asset of operating lease. cui_RoyaltyExpenseOffsetAgainstNoteReceivable Royalty Expense, Offset Against Note Receivable The amount of royalty expense offset against note receivable during the period. Non-cash investment in equity method investment Represents non-cash investment-equity method investment, including convertible notes receivable, certain fixed assets, other intangible assets, inventory, prepaid assets, open purchases orders, and future research and development expenditure. cui_WeightedAverageSharesOutstandingUnissued Weighted Average Shares Outstanding, Unissued The number of weighted average shares outstanding that currently remain unissued. Pretax gain on assets contributed as part of the purchase of VPS The amount of gain (loss) on asset contributed as part of purchase in a discontinued operation. cui_SuretyBondGuarantee Surety Bond Guarantee The amount of surety bond guarantee. Sub-limit for Non-loan Party Subsidiaries [Member] Related to the sub-limit for non-loan party subsidiaries. Liabilities held for sale, noncurrent portion Total noncurrent liabilities * cui_IncomeLossBeforeIncomeTaxesNoncontrollingInterest Loss before income taxes The amount of income (loss) before income taxes, noncontrolling interest. cui_ProjectGuaranteePercentOfProjectCompleted Project Guarantee, Percent of Project Completed The percent of project completed for a project guarantee. Other long-term liabilities cui_StockIssuedDuringPeriodRoyaltyPaymentsValue Stock Issued During Period, Royalty Payments, Value The value of stock issued during the period for royalty payments. cui_StockIssuedDuringPeriodRoyaltyPaymentsShares Stock Issued During Period, Royalty Payments, Shares The number of shares of stock issued during the period for royalty payments. Comprehensive net loss cui_EquityMethodInvestmentSummarizedFinancialInformationComprehensiveNetProfit The amount of comprehensive net profit reported by an equity method investment of the entity. Foreign currency translation adjustment cui_EquityMethodInvestmentSummarizedFinancialInformationForeignCurrencyTranslationAdjustment The amount of foreign currency translation adjustment reported by an equity method investment of the entity. Lease, Cost and Other Lease Information [Table Text Block] Tabular disclosure of lessee's lease cost, and other lease information. Adjusted comprehensive loss cui_EquityMethodInvestmentSummarizedFinancialInformationForeignAdjustedComprehensiveProfit The amount of foreign adjusted comprehensive profit reported by an equity method investment of the entity. Add back excluded acquisition intangible amortization, net cui_EquityMethodInvestmentSummarizedFinancialInformationExcludedAcquisitionIntangibleAmortization The amount of add back excluded acquisition intangible amortization reported by an equity method investment of the entity. cui_EmploymentAgreementsAccruedEmployeeCompensation Employment Agreements, Accrued Employee Compensation The amount of accrued compensation payable to an employee or executive in relation to the employment agreement. Foreign Exchange Forward [Member] us-gaap_StockholdersEquity Total stockholders' equity Balance Balance us-gaap_ContractWithCustomerLiabilityNoncurrent Long-term contract liabilities, January 1 Long-term contract liabilities, December 31 Lease Disclosure [Text Block] The entire disclosure for operating, finance, sale leaseback leases. Option Indexed to Issuer's Equity, Type [Domain] cui_NotesReceivableInterestRate Notes Receivable, Interest Rate Represents the interest rate for notes receivable. Virtual Power Systems [Member] Represents information about Virtual Power Systems. Reach Construction Group, LLC [Member] Information pertaining to Reach Construction Group, LLC. Interest Rate Swap [Member] Sale Leaseback Transaction to Sell Tualatin Headquarters And Warehouse [Member] Represents the sale leaseback transaction to sell Tualatin headquarters and warehouse. Option Indexed to Issuer's Equity [Axis] Lease Related to Relocated to Another Rented Office and Warehouse [Member] Represents lease related to relocated to another rented office and warehouse. Common Stock Outstanding [Member] Represents common stock outstanding. Vehicles, Equipment, and On Accommodations for Vesting Personnel [Member] Represents information related to vehicles, equipment, and on accommodations for vesting personnel. Deferred income taxes Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing and discontinued operations.