Document And Entity Information
Dividend yield
Note To Financial Statement Details Textual
Foreign exchange forward contracts
Significant Accounting Policies
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Total
Note 1 - Summary of Significant Accounting Policies
Due in one year or less, amortized cost
Note 2 - Goodwill and Purchased Intangible Assets
Risk-free interest rate
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value, Total
Note 3 - Borrowings and Credit Agreements
Due in one year or less, fair value
Xcerra Integration Program [Member]
Represents Xcerra Integration Program.
Note 4 - Restructuring Charges
Due after 1 year through 5 years, fair value
MCT Integration Program [Member]
Represents MCT Integration Program.
Equity Based Performance Stock Units Granted in 2020, 2019, 2018, and 2017 [Member]
Represents equity based performance stock unites granted in 2020, 2019, 2018, and 2017.
Note 5 - Financial Instruments Measured at Fair Value
Due after 5 years through 10 years, fair value
Note 6 - Employee Benefit Plans
Operating lease assets acquired in MCT acquisition
The amount of operating lease assets that an Entity acquires in a noncash (or part noncash) acquisition. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.
Note 7 - Business Acquisitions
Financing lease assets acquired in MCT acquisition
The amount of finance lease assets that an Entity acquires in a noncash (or part noncash) acquisition. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.
Note 8 - Derivative Financial Instruments
London Interbank Offered Rate (LIBOR) 1 [Member]
Interest rate at which a bank borrows funds from other banks in the London interbank market.
Note 10 - Income Taxes
Note 11 - Segment and Geographic Information
Change in unrealized gain/loss on investments
Changes in unrealized gains and losses on investments, net of tax
Change in unrealized gain/loss on investments, net of tax
Note 12 - Leases
Note 14 - Guarantees
Expected volatility
Note 16 - Accumulated Other Comprehensive Income (Loss)
us-gaap_LiabilitiesCurrent
Total current liabilities
Schedule II - Valuation and Qualifying Accounts
Note 1 - Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Details)
Other comprehensive income (loss), net of tax
Note 1 - Summary of Significant Accounting Policies - Inventories (Details)
Expected term (Year)
Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details)
Asset-Backed Securities [Member]
Note 1 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details)
Note 2 - Goodwill and Purchased Intangible Assets - Summary of Borrowings (Details)
us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
Adjustments related to postretirement benefits, net of tax
Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details)
Note 3 - Borrowings and Credit Agreements - Summary of Borrowings (Details)
Note 3 - Borrowings and Credit Agreements - Debt Principal Payments for the Next Five Years and Thereafter (Details)
US States and Political Subdivisions Debt Securities [Member]
Note 4 - Restructuring Charges - Charges Related to the Wind Down Plan (Details)
Note 5 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details)
Note 5 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details)
Swiss Plan [Member]
Information about the Swiss Plan.
Note 5 - Financial Instruments Measured at Fair Value - Assets Measured at Fair Value on Recurring Basis (Details)
Debt Security, Government, Non-US [Member]
Note 6 - Employee Benefit Plans - Net Periodic Benefit Cost of Swiss Plan (Details)
Note 6 - Employee Benefit Plans - Benefit Obligation, Fair Value of Plan Assets, Funded Status and Liability of Swiss Plan (Details)
Note 6 - Employee Benefit Plans - Weighted-average Actuarial Assumptions to Determine Benefit Obligation and Net Periodic Benefit Cost (Details)
Note 6 - Employee Benefit Plans - Post-retirement Benefit Obligation to Funded Status and Liability (Details)
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent
Foreign currency translation adjustments, net of tax
Granted, wt. avg. (in dollars per share)
Note 6 - Employee Benefit Plans - Stock Option Activity Under Share-based Compensation Plans (Details)
Released, wt. avg. (in dollars per share)
Note 6 - Employee Benefit Plans - Restricted Stock Unit Activity Under Share-based Compensation Plans (Details)
Cancelled, wt. avg. (in dollars per share)
US Treasury Securities [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Outstanding, beginning of year, wt. avg. (in dollars per share)
Outstanding, end of year, wt. avg. (in dollars per share)
Note 6 - Employee Benefit Plans - Performance Based Stock Unit Activity Under Share-based Compensation Plans (Details)
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax
Note 6 - Employee Benefit Plans - Weighted-average Assumptions Used to Value Share-based Awards Granted (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Cancelled, units (in shares)
Note 6 - Employee Benefit Plans - Reported Share-based Compensation in Consolidated Financial Statements (Details)
us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax
Impact of sale of PCB Test business
us-gaap_DeferredCompensationLiabilityCurrent
Deferred Compensation Liability, Current
Note 7 - Business Acquisitions - Purchase Price Allocation (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Outstanding, beginning of year, units (in shares)
Outstanding, end of year, units (in shares)
Foreign currency translation adjustments
us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
Changes in cumulative translation adjustment
Note 7 - Business Acquisitions - Preliminary Allocation of Intangible Assets (Details)
Schedule of Derivative Instruments [Table Text Block]
Note 8 - Derivative Financial Instruments - Foreign Currency Forward Contracts Outstanding (Details)
Real Estate Investments [Member]
This element represents direct equity investments in real estate projects
Note 8 - Derivative Financial Instruments - Locations and Amounts of Gains (Loss) (Details)
Note 10 - Income Taxes - Components of Provision (Benefit) for Income Taxes for Continuing Operations (Details)
Granted, units (in shares)
Alternative Investments [Member]
Fair value of investments in certain entities that calculate net asset value per share, including, but not limited to, by unit, membership interest, or other ownership interest. Investments include, but are not limited to, investments in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds.
Note 10 - Income Taxes - Income (Loss) Before Income Taxes From Continuing Operations (Details)
Corporate Debt Securities [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Released, units (in shares)
Note 10 - Income Taxes - Components of Deferred Tax Assets and Liabilities (Details)
Note 10 - Income Taxes - Reconciliation of Income Tax Computed at U.S. Federal Statutory Tax Rate to Provision (Benefit) (Details)
us-gaap_LongTermDebtCurrent
Long-Term Debt, Current Maturities
Less: current portion
Note 10 - Income Taxes - Reconciliation of Income Tax Computed at U.S. Federal Statutory Tax Rate to Provision (Benefit) (Details) (Parentheticals)
Note 10 - Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details)
Note 11 - Segment and Geographic Information - Summary of Current Segments (Details)
Current installments of long-term debt
Note 11 - Segment and Geographic Information - Customers Comprising 10% of Consolidated Sales (Details)
Note 11 - Segment and Geographic Information - Summary of Net Sales to Customers, Attributed to Countries (Details)
Other comprehensive loss, net of tax
us-gaap_OtherComprehensiveIncomeLossNetOfTax
Note 11 - Segment and Geographic Information - Summary of Property, Plant and Equipment and Other Long Lived Assets in Geographical Area (Details)
Note 12 - Leases - Balance Sheet Information (Details)
Note 12 - Leases - Lease Expense (Details)
Note 12 - Leases - Future Minimum Lease Payments (Details)
Note 12 - Leases - Cash Flow Information (Details)
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Debt Securities, Available-for-Sale, Unrealized Loss Position
Note 14 - Guarantees - Changes in Accrued Warranty (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value
Note 16 - Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Loss (Details)
Note 16 - Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss, Net of Tax (Details)
Schedule II - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Details)
Notes To Financial Statements
Notes To Financial Statements [Abstract]
Weighted-average grant date fair value per share (in dollars per share)
Financial Instruments [Domain]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Outstanding and exercisable, weighted average exercise price, balance (in dollars per share)
Outstanding and exercisable, weighted average exercise price, balance (in dollars per share)
Customer advances
Financial Instrument [Axis]
cohu_PercentageOfFairValueToDeterminePriceOfCommonStock
Percentage of Fair Value to Determine Price of Common Stock
Percentage of the Fair Value to Determine the price of common stock.
cohu_EmployeeStockPurchasePlanSharesReservedforFutureIssuance
Employee Stock Purchase Plan, Shares Reserved for Future Issuance (in shares)
The shares reserved for future issuance under the employee stock purchase plan.
Exercised, weighted average exercise price (in dollars per share)
us-gaap_AccruedLiabilitiesCurrent
Accrued Liabilities, Current
Accrued compensation and benefits
Income taxes payable
Accounts payable
Unvested Restricted Stock Units [Member]
The unvested restricted stock units.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Outstanding and exercisable balance (in shares)
Outstanding and exercisable balance (in shares)
Other accrued liabilities
Other Accrued Liabilities, Current
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Accrued warranty
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage
Swiss Franc Foreign Exchange Forward [Member]
Foreign exchange forward traded on an exchange for options or future contracts to buy or sell Swiss Francs, at a specified date, at a fixed exercise exchange rate.
Euro Foreign Exchange Forward [Member]
Foreign exchange forward traded on an exchange (examples include but are not limited to the International Securities Exchange, Philadelphia Stock Exchange, or the Chicago Mercantile Exchange) for options or future contracts to buy or sell Euros, at a specified date, at a fixed exercise exchange rate.
Current liabilities:
Vesting [Axis]
Vesting [Domain]
us-gaap_Assets
Assets
us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation
Disposal Group, Including Discontinued Operation, Assets, Total
Plan Name [Axis]
Plan Name [Domain]
us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1
Disposal Group, Including Discontinued Operation, Goodwill
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 (Year)
us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssets
Disposal Group, Including Discontinued Operation, Intangible Assets
us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Income tax benefit
us-gaap_DeferredIncomeTaxAssetsNet
Other assets (long-term)
Share-Based Payment Arrangement [Text Block]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
STMicroelectronics [Member]
In relation to STMicroelectronics.
Accruals, adjustments and releases from statute expirations
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income tax accruals adjustments and releases from statute expiration.
us-gaap_ContractWithCustomerAssetNet
Contract with Customer, Asset, after Allowance for Credit Loss, Total
cohu_UnrecognizedTaxBenefitsIncreaseDecreaseRelatedToTransferPricing
Unrecognized Tax Benefits, Increase (Decrease) Related to Transfer Pricing
The amount of increase or decrease of unrecognized tax benefits related to transfer pricing.
Dividend, net of foreign tax credits
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deemed dividends.
Long-term Lease Liabilities [Member]
Represents long-term lease liabilities.
Award Type [Domain]
Award Type [Axis]
Accumulated Amortization
Business Divestitures [Policy Text Block]
Description of all Business Divestitures recognized during the period
Intangible assets, net
EQT Retention Sum Liability [Member]
In relation to the EQT Retention Sum Liability.
Uniform capitalization
Amount, before allocation of valuation allowance, of deferred tax asset attributable to uniform capitalization.
Gross Carrying Amount, finite-lived intangible assets
us-gaap_CapitalizedComputerSoftwareGross
Capitalized Computer Software, Gross
cohu_BusinessCombinationRetentionSumLiabilityForPotentialAdjustments
Business Combination, Retention Sum Liability for Potential Adjustments
In reference to the Retention Sum Liability for Potential Adjustments in relation to Business Acquisitions.
Commitments and Contingencies Disclosure [Text Block]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Less accumulated depreciation and amortization
cohu_CollectionTermRange
Collection Term Range (Year)
The collection term range.
Property, plant and equipment, net
Property plant and equipment, net
Property, plant and equipment, net
Goodwill
Goodwill
Beginning balance
Ending balance
Inventory, receivable and warranty reserves
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from inventory and warranty reserves.
Intangible assets and other acquisition basis differences
Amount of deferred tax liability attributable to taxable temporary differences from acquisition basis differences.
Property, plant and equipment
cohu_RepurchaseAndRetirementOfStockValue
Repurchase and retirement of stock
The amount of repurchase and retirement of stock, including treasury stock.
Equiptest Engineering Pte Ltd. [Member]
Related to Equiptest Engineering Pte Ltd.
Rest of the World [Member]
The rest of the world.
Accrued retiree benefits
Contract amount
Contract amount
Derivative Instrument [Axis]
Derivative Contract [Domain]
Estimated fair value
Short-term investments
Additions (reductions) not charged to expense
Amount of increase (decrease) in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, not charged (credited) to costs and expenses.
Income tax provision
Income Tax Expense (Benefit)
Additions (reduction) charged (credited) to expense
Amount of increase (decrease) in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges (credits) to costs and expenses.
us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
Gain on business divestitures
us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Defined Contribution Plan, Employer Discretionary Contribution Amount
us-gaap_GeneralAndAdministrativeExpense
Corporate expenses
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
cohu_DefinedBenefitPlanExpectedFutureEmployeeAndEmployerContributionsNextTwelveMonths
Defined Benefit Plan, Expected Future Employee and Employer Contributions, Next Twelve Months
Represents the expected future employee and employer contributions, next twelve months.
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Defined Contribution Plan, Employer Matching Contribution, Percent of Match
Cash and cash equivalents
Business Combination, Goodwill, and Intangible Assets Disclosure [Text Block]
The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities and the entire disclosure for the aggregate amount of goodwill and a description of intangible assets.
us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Plan assets at end of year
Fair value of plan assets at beginning of year
Fair value of plan assets at end of year
Funded status
Net liability at end of year
Benefit obligation at beginning of year
Benefit obligation at end of year
us-gaap_DefinedBenefitPlanBenefitObligation
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years
Employer contributions
us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
Defined Benefit Plan, Expected Future Benefit Payment, Year Two
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
Defined Benefit Plan, Expected Future Benefit Payment, Year Three
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
Defined Benefit Plan, Expected Future Benefit Payment, Year Four
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
Defined Benefit Plan, Expected Future Benefit Payment, Year Five
Amendment Flag
City Area Code
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Defined Benefit Plan, Expected Future Benefit Payment, Year One
us-gaap_GainLossOnSaleOfBusiness
Gain (Loss) on Disposition of Business
Gain on sale of PCB Test business (2)
New Accounting Pronouncements, Policy [Policy Text Block]
us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year
us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate
Rate of return on assets
us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease
Compensation increase
Compensation increase
Current Fiscal Year End Date
Discount rate
us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate
Discount rate
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate
Valuation and Qualifying Accounts Disclosure [Table Text Block]
The tabular disclosure of valuation and qualifying accounts and reserves.
Accumulated benefit obligation at beginning of year
Accumulated benefit obligation at end of year
us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Document Fiscal Period Focus
Document Fiscal Year Focus
Document Period End Date
Entity File Number
Entity Emerging Growth Company
us-gaap_WriteOffOfDeferredDebtIssuanceCost
Deferred Debt Issuance Cost, Writeoff
Document Type
Loss on extinguishment of debt
us-gaap_GainsLossesOnExtinguishmentOfDebt
Gain (Loss) on Extinguishment of Debt
Loss on extinguishment of debt
Entity Small Business
Return on assets, net of actuarial loss
Entity Shell Company
Participant contributions
us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
Settlements
Document Information [Line Items]
Document Information [Table]
us-gaap_DefinedBenefitPlanSettlementsPlanAssets
Settlements
us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss
Foreign currency exchange adjustment
Entity Public Float
us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid
Benefits paid
Entity Filer Category
Entity Current Reporting Status
Costs accrued
Restructuring charges (Note 4)
Restructuring Charges
Entity Voluntary Filers
us-gaap_BusinessCombinationAcquisitionRelatedCosts
Business Combination, Acquisition Related Costs
Entity Well-known Seasoned Issuer
us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant
Participant contributions
Actuarial (gain) loss
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)
Foreign currency exchange adjustment
Plan change
Settlements
us-gaap_DefinedBenefitPlanSettlementsBenefitObligation
Impairment charges
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)
us-gaap_GoodwillImpairmentLoss
Goodwill, Impairment Loss
Net sales percentage
Statement of Comprehensive Income [Abstract]
Entity Tax Identification Number
Entity Central Index Key
Entity Registrant Name
Entity [Domain]
Legal Entity [Axis]
Customer Concentration Risk [Member]
Entity Address, Address Line One
Amortization of cost
Amortization of Intangible Assets
ecd_NonRule10b51ArrTrmntdFlag
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Entity Address, City or Town
ecd_Rule10b51ArrTrmntdFlag
Rule 10b5-1 Arrangement Terminated [Flag]
ecd_Rule10b51ArrAdoptedFlag
Rule 10b5-1 Arrangement Adopted [Flag]
Entity Address, Postal Zip Code
Entity Address, State or Province
ecd_NonRule10b51ArrAdoptedFlag
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Concentration Risk Type [Axis]
Material Terms of Trading Arrangement [Text Block]
Concentration Risk Type [Domain]
ecd_TrdArrIndTitle
Trading Arrangement, Individual Title
ecd_TrdArrIndName
Trading Arrangement, Individual Name
ecd_TrdArrSecuritiesAggAvailAmt
Trading Arrangement, Securities Aggregate Available Amount
Entity Common Stock, Shares Outstanding
ecd_TrdArrAdoptionDate
Trading Arrangement Adoption Date
Revenue Benchmark [Member]
us-gaap_CashSurrenderValueOfLifeInsurance
Cash Surrender Value of Life Insurance
Trading Symbol
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
Local Phone Number
us-gaap_TableTextBlock
Notes Tables
us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Selling, general and administrative
us-gaap_ProvisionForDoubtfulAccounts
Provision for Doubtful Accounts
us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax
Raw materials and purchased parts
Finished goods
Work in process
cohu_IncreaseDecreaseOfEarningPerShareDueToImpactOfTaxHolidays
Increase (Decrease) of Earning Per Share Due To Impact Of Tax Holidays (in dollars per share)
The increase or decrease of earning per share due to impact of tax holidays.
Research and development
cohu_IncreaseDecreaseInAccruedCompensationWarrantyAndOtherLiabilities
Accrued compensation, warranty and other liabilities
The increase (decrease) during the period in accrued salaries, warranty, and other liabilities.
Derivative Instruments, Gain (Loss) [Table Text Block]
us-gaap_InterestExpense
Interest expense
us-gaap_AmortizationOfFinancingCosts
Amortization of Debt Issuance Costs
Defined Benefit Plan, Equity Securities [Member]
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Subsequent Event [Member]
Defined Benefit Plan, Plan Assets, Category [Axis]
Defined Benefit Plan, Plan Assets, Category [Domain]
Schedule of Inventory, Current [Table Text Block]
Goodwill and other intangible assets
Subsequent Event Type [Axis]
Subsequent Event Type [Domain]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
Finite-Lived Intangible Asset, Expected Amortization, after Year Five
Fair Value Measurement, Policy [Policy Text Block]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
Finite-Lived Intangible Asset, Expected Amortization, Year Two
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
Finite-Lived Intangible Asset, Expected Amortization, Year Three
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
Finite-Lived Intangible Asset, Expected Amortization, Year Four
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
Finite-Lived Intangible Asset, Expected Amortization, Year Five
Segment Reporting, Policy [Policy Text Block]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
Finite-Lived Intangible Asset, Expected Amortization, Year One
SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]
Foreign Currency Transactions and Translations Policy [Policy Text Block]
Other assets
Lessee, Leases [Policy Text Block]
SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis]
Remaining Useful Life (Year)
Finite-Lived Intangible Asset, Useful Life (Year)
Earnings Per Share, Policy [Policy Text Block]
Intangible assets, estimated fair value
Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with a finite or indefinite life, from an acquisition.
Comprehensive Income, Policy [Policy Text Block]
Income Tax, Policy [Policy Text Block]
Internal Use Software, Policy [Policy Text Block]
us-gaap_LesseeOperatingLeaseRenewalTerm
Lessee, Operating Lease, Renewal Term (Year)
Costs Associated with Exit or Disposal Activities or Restructurings, Policy [Policy Text Block]
us-gaap_SharesIssuedPricePerShare
Shares Issued, Price Per Share (in dollars per share)
us-gaap_AssetsCurrent
Total current assets
Share-Based Payment Arrangement [Policy Text Block]
Equity [Text Block]
Kita Term Loans [Member]
Represents information pertaining to term loans related to the Kita acquisition.
Advertising Cost [Policy Text Block]
Ismeca [Member]
Represents information pertaining to Ismeca, a wholly-owned subsidiary of Cohu.
cohu_NumberOfAvailableLinesOfCredit
Number of Available Lines of Credit
Represents the number of available lines of credit as of the balance sheet date.
Standard Product Warranty, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsValuationAllowance
Deferred Tax Assets, Valuation Allowance
Less valuation allowance
Commitments and Contingencies, Policy [Policy Text Block]
Other current assets
us-gaap_DeferredTaxAssetsNet
Total deferred tax assets
Total debt
Represents the aggregate of total long-term debt, including current maturities and short-term debt, before financing fees and discount.
Debt, Policy [Policy Text Block]
Prepaid expenses
Other
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]
Goodwill and Intangible Assets, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsGross
Gross deferred tax assets
us-gaap_DeferredIncomeTaxLiabilities
Total deferred tax liabilities
Inventories
Total inventories
Net sales
Capitalized R&D
Foreign transaction gain (loss)
cohu_ValuationAllowancesAndReservesDeductionsRecoveries
Deductions/write-offs
Amount of decrease (increase) in valuation and qualifying accounts and reserves.
us-gaap_PropertyPlantAndEquipmentUsefulLife
Property, Plant and Equipment, Useful Life (Year)
Accounts receivable, net
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Accrued employee benefits
us-gaap_NumberOfOperatingSegments
Number of Operating Segments
PCB Test [Member]
Relating to the segment, PCB Test.
us-gaap_NumberOfReportableSegments
Number of Reportable Segments
Semiconductor Test and Inspection [Member]
Relating to the segment, Semiconductor Test & Inspection.
us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
Stock-based compensation
Building and Building Improvements [Member]
Building [Member]
Building Improvements [Member]
Land and Land Improvements [Member]
Short-term investments
Property, Plant and Equipment, Policy [Policy Text Block]
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table Text Block]
Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite or indefinite life, by either major class or business segment.
Long-Lived Tangible Asset [Axis]
Segment Reporting Disclosure [Text Block]
Long-Lived Tangible Asset [Domain]
Tax credit carryforwards
Net operating loss carryforwards
Current assets:
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
Cash and cash equivalents at beginning of year
Cash and cash equivalents at end of year
Inventory, Policy [Policy Text Block]
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net increase (decrease) in cash and cash equivalents
Over-Allotment Option [Member]
Interest income
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash provided by (used in) financing activities
Director [Member]
Sale of Stock [Axis]
Sale of Stock [Domain]
Effect of exchange rate changes on cash and cash equivalents
us-gaap_OperatingIncomeLoss
Income from operations
us-gaap_DeferredTaxLiabilitiesOther
Other
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
Other (expense) income:
us-gaap_DeferredTaxLiabilities
Net deferred tax liabilities
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash provided by (used in) investing activities
Derivatives, Policy [Policy Text Block]
Unremitted earnings of foreign subsidiaries
Concentration Risk, Credit Risk, Policy [Policy Text Block]
us-gaap_CostsAndExpenses
Costs and Expenses
us-gaap_PaymentsForRepurchaseOfCommonStock
Acquisition of treasury stock
Cost and expenses:
cohu_DefinedBenefitPlanBenefitObligationBenefitsPaidRecovered
Benefits paid
Amount of the payment (recovery) to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, life insurance benefits, and legal, educational and advisory services.
Title of Individual [Domain]
Proceeds received from issuance of common stock, net of fees
Proceeds from Issuance of Common Stock
U.S. State
Title of Individual [Axis]
Foreign
cohu_DefinedBenefitPlanPlanAssetsBenefitsPaidRecovered
Benefits paid
Amount of payment (recovery) to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.
us-gaap_DeferredForeignIncomeTaxExpenseBenefit
Foreign
U.S. Federal
us-gaap_DeferredFederalIncomeTaxExpenseBenefit
U.S. Federal
cohu_LesseeLeaseRemainingTermOfContract
Lessee, Lease, Remaining Term of Contract (Year)
Remaining term of lessee's operating and finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.
Lessee, Leases [Text Block]
The entire disclosure for operating and finance leases of lessee.
us-gaap_CurrentIncomeTaxExpenseBenefit
Total current
Construction Loans [Member]
GILTI, net of foreign tax credits
us-gaap_RevenueRemainingPerformanceObligation
Revenue, Remaining Performance Obligation, Amount
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign
Income from continuing operations, Foreign
cohu_LeaseRightofuseAsset
Total lease assets
Amount of lessee's right to use underlying asset under finance and operating lease.
Other Accrued Liabilities [Member]
Related to other accrued liabilities.
Leases, Balance Sheet Information [Table Text Block]
Tabular disclosure of balance sheet information for leases.
2025, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in second fiscal year following latest fiscal year.
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Total
Profit (loss) from continuing operations before taxes
Lessee, Lease, Liability, Maturity [Table Text Block]
Tabular disclosure of undiscounted cash flows of lessee's operating and finance lease liability.
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
Income (loss) from continuing operations, U.S.
Present value of lease liabilities, total
cohu_LeaseLiability
Total lease liabilities
Present value of lessee's discounted obligation for lease payments from finance and operating lease.
Thereafter, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due after fifth fiscal year following latest fiscal year.
2028, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fifth fiscal year following latest fiscal year.
2027, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fourth fiscal year following latest fiscal year.
2026, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in third fiscal year following latest fiscal year.
Lease, Cash Flow Information [Table Text Block]
Tabular disclosure of the cash flow information for leases.
cohu_LesseeLeaseLiabilityUndiscountedExcessAmount
Less: Interest, total
Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating and finance lease.
ICFR Auditor Attestation Flag
cohu_LesseeLeaseLiabilityPaymentsDue
Total lease payments, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease.
Comprehensive Income (Loss) Note [Text Block]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Debt Securities and Cash [Member]
Information related to debt securities and cash.
State and Local Jurisdiction [Member]
Income Tax Authority [Axis]
Income Tax Authority [Domain]
Disaggregation of Revenue [Table Text Block]
Domestic Tax Authority [Member]
Foreign Tax Authority [Member]
us-gaap_RepaymentsOfLongTermDebt
Repayments of Long-Term Debt
Repayments of long-term debt
Cash and Cash Equivalents, Policy [Policy Text Block]
us-gaap_UnrecognizedTaxBenefits
Balance at beginning of year
Balance at end of year
us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Unrecognized Tax Benefits that Would Impact Effective Tax Rate
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]
Pre Age 65 Plan [Member]
Relating to the pre age 65 plan.
Basis of Accounting, Policy [Policy Text Block]
Post Age 65 Plan [Member]
Relating to the post age 65 plan.
us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
Reductions due to lapse of the statute of limitations
us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromForeignCurrencyTranslation
Foreign exchange rate impact
Foreign exchange rate impact
MCT Worldwide, LLC [Member]
Relating to MCT Worldwide, LLC.
Additions/(Reductions) for tax positions of prior years
us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
Additions/(Reductions) for tax positions of prior years
Additions for tax positions of current year
Vesting Over One Year Period [Member]
Represent a year vesting period.
Vesting Over Two Year Period [Member]
Represent two year vesting period.
Vesting Over Four Year Period [Member]
Represent four year vesting period.
Vest on the Third Anniversary of Awards Grant [Member]
Represent awards that are versing on the third anniversary of grant.
PCB Test Business [Member]
Represents PCB test business.
cohu_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessBeforeTax
Reclassification due to sale of PBC Test Business, before tax
Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of business.
Reclassification due to sale of PBC Test Business, tax
Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of business.
Auditor Name
cohu_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessNetOfTax
Reclassification due to sale of PBC Test Business, net of tax
Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of business.
Auditor Firm ID
Auditor Location
Excess executive compensation
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to excess executive compensation.
Effect of dilutive stock options and restricted stock units (in shares)
us-gaap_TaxCreditCarryforwardAmount
Tax Credit Carryforward, Amount
us-gaap_ProductWarrantyAccrualNoncurrent
Product Warranty Accrual, Noncurrent
Other accrued liabilities
us-gaap_OtherAccruedLiabilitiesNoncurrent
Other Accrued Liabilities, Noncurrent
us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization
Finance Lease, Right-of-Use Asset, Accumulated Amortization
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)
Blackrock [Member]
Represents the entity of Blackrock, a related party of the company.
us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Weighted Average Number of Shares Outstanding, Diluted
Diluted (in shares)
Analog Devices [Member]
Represents Analog Devices.
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Proceeds from revolving line of credit and construction loans
Statement of Financial Position [Abstract]
us-gaap_EarningsPerShareDiluted
Diluted: (in dollars per share)
Weighted average common shares outstanding (in shares)
Basic (in shares)
Cost of sales (1)
Business Acquisition [Axis]
us-gaap_EarningsPerShareBasic
Basic: (in dollars per share)
Business Acquisition, Acquiree [Domain]
Statement of Cash Flows [Abstract]
Warranty liability transferred
Represents warrant liability transferred for product warranty accrual.
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]
Statement of Stockholders' Equity [Abstract]
Property, Plant and Equipment, Net [Member]
Represents property, plant and equipment, net.
Net issuance (repurchases) of stock, including awards settled in cash
Represents net issuance (repurchase) of stock, including awards settled in cash.
cohu_ExtinguishmentOfDebtDecreaseDeferredFinancingCosts
Extinguishment of Debt Decrease Deferred Financing Costs
Represents decrease deferred financing costs for extinguishment of debt.
us-gaap_RestructuringReserveTranslationAdjustment
Impact of currency exchange
Interest on lease liabilities
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]
us-gaap_FinanceLeaseLiabilityPaymentsDue
Total lease payments, finance leases
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
Amortization of leased assets
Investments Classified by Contractual Maturity Date [Table Text Block]
2028, finance leases
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Thereafter, finance leases
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount
Less: Interest, finance leases
2024, finance leases
2025, finance leases
Unrealized Gain (Loss) on Investments [Table Text Block]
2026, finance leases
2027, finance leases
Restructuring Plan [Axis]
Restructuring Plan [Domain]
Other Restructuring [Member]
Type of Restructuring [Domain]
us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent
Finance leases
Employee Severance [Member]
Restructuring and Related Activities Disclosure [Text Block]
Restructuring and Related Costs [Table Text Block]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
Restructuring Type [Axis]
us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1
Finance leases (Year)
Other, net
Cash flows from financing activities:
U.S. statutory rate
Change in valuation allowance
us-gaap_IncomeTaxReconciliationTaxExemptIncome
Exemption of PTG gain
Corporate, Non-Segment [Member]
Deferred profit
Deferred Profit
The carrying value of deferred revenue, net of expenses, as of the balance sheet date that is expected to be recognized as such within one year or the normal operating cycle, if longer.
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
Net assets acquired
Cash received from disposition of business, net of cash paid
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Liabilities assumed
us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Payment for purchase of business, net of cash received
Class of Stock [Axis]
us-gaap_CashAcquiredFromAcquisition
Cash Acquired from Acquisition
Stock-based compensation
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
us-gaap_PaymentsToAcquireBusinessesGross
Payments to Acquire Businesses, Gross
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
Total assets acquired
State income taxes, net of federal tax benefit
Foreign rate differential
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Property, plant and equipment
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets
Other assets
us-gaap_IncomeTaxReconciliationTaxCreditsResearch
Federal R&D credits
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles
Intangible assets
Tax provision at U.S. 21% statutory rate
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets
Current assets, including cash received
cohu_UnrecognizedTaxBenefitsInterestExpenseNetOfAccruedInterestReversed
Unrecognized Tax Benefits, Interest Expense, Net of Accrued Interest Reversed
Amount of interest expense net of accrued interest reversed for an underpayment of income taxes.
Not Designated as Hedging Instrument [Member]
Income Tax Disclosure [Text Block]
Hedging Designation [Axis]
Hedging Designation [Domain]
Schedule of Maturities of Long-Term Debt [Table Text Block]
Schedule of Debt [Table Text Block]
us-gaap_BusinessCombinationConsiderationTransferred1
Business Combination, Consideration Transferred
Inventory capitalized as capital assets
Represents information about inventory capitalized as property, plant and equipment.
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
Finite-lived intangible assets, estimated fair value
Finite-lived intangible assets, average useful life (Year)
cohu_StockRepurchaseProgramAdditionalAuthorizedAmount
Stock Repurchase Program, Additional Authorized Amount
Amount of additional stock repurchase plan authorized.
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
cohu_DebtSecuritiesAvailableforsaleUnrealizedLossPositionAmortizedCost
Debt Securities, Available-for-Sale, Unrealized Loss Position, Amortized Cost
Amount of investment in debt security measured at amortized cost, in unrealized loss position.
Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]
Sales and maturities of short-term investments
Semiconductor Equipment [Member]
Semiconductor equipment as a business segment.
us-gaap_GoodwillAndIntangibleAssetImpairment
Goodwill and Intangible Asset Impairment, Total
cohu_RestructuringExpenses
Restructuring Expenses
The amount of expenses associated with restructuring.
Schedule of Nonvested Performance-Based Units Activity [Table Text Block]
cohu_AccumulatedOtherComprehensiveIncomeLossUnrealizedGainLossOnInvestmentsNetOfTax
Accumulated net unrealized gain/loss on investments
Amount of accumulated other comprehensive income (loss) from unrealized gain (loss) on investments, net of taxes.
PCB Test Business Sale [Member]
Related to PCB test business sale.
Guarantees [Text Block]
Schedule of Net Benefit Costs [Table Text Block]
Schedule of Net Funded Status [Table Text Block]
Third Facility [Member]
Represents third facility.
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan [Table Text Block]
Defined Benefit Plan, Assumptions [Table Text Block]
cohu_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesAvailableForIssue
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Shares Available for Issue
Represents share based compensation arrangement by share based payment award percentage of shares available for issue.
Equity Based Performance Stock Units [Member]
Equity based performance stock units.
2024, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in next fiscal year following latest fiscal year.
us-gaap_PaymentsToAcquireShortTermInvestments
Purchases of short-term investments
Employee Stock Purchase Plan [Member]
Employee stock purchase plan.
Retirement Plan Name [Axis]
Retirement Plan Name [Domain]
us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets
Proceeds from Sales of Business, Affiliate and Productive Assets
Goodwill and Intangible Assets Disclosure [Text Block]
Schedule of Goodwill [Table Text Block]
Revolving Credit Facility [Member]
Net cash received from sale of land, facility and assets
Postretirement Health Coverage [Member]
Retirement Plan Type [Axis]
Retirement Plan Type [Domain]
Property, plant and equipment purchases included in accounts payable
Credit Facility [Axis]
Credit Facility [Domain]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Trademarks and Trade Names [Member]
Trade Names [Member]
Indefinite-Lived Intangible Assets [Axis]
Indefinite-Lived Intangible Assets, Major Class Name [Domain]
Capital expenditures
Purchases of property, plant and equipment
cohu_StandardProductWarrantyTerm
Standard Product Warranty Term (Month)
Describes the term of the product warranty.
Order or Production Backlog [Member]
Weighted average shares used in computing income per share:
Noncompete Agreements [Member]
Cash paid for income taxes
Developed Technology Rights [Member]
Current and long-term operating lease liabilities
Supplemental disclosure of cash flow information:
cohu_DebtInstrumentAmortizationPercentageOfPrincipalAmount
Debt Instrument, Amortization, Percentage of Principal Amount
Percentage of quarterly installments of the original principal, with balance payable at maturity.
Secured Term Loan Facility [Member]
Represents the information pertaining to the secured term loan facility.
us-gaap_LongTermDebtFairValue
Long-Term Debt, Fair Value
us-gaap_SubleaseIncome
Sublease income
Indefinite-lived In Process Research and Development [Member]
In process investigation of new knowledge useful in developing new product or service or new process or technique or improvement to existing product or process, and translation of knowledge into plan or design for new product or process or for improvement to existing product or process classified as indefinite-lived.
Customer Relationships [Member]
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]
Net income
Net income
Net income (loss)
Restricted Stock Units (RSUs) [Member]
Performance Shares [Member]
Share-Based Payment Arrangement, Option [Member]
Impact of currency exchange
us-gaap_GoodwillForeignCurrencyTranslationGainLoss
Additions
us-gaap_GoodwillAcquiredDuringPeriod
Secured Overnight Financing Rate (SOFR) [Member]
Interest rate based on U.S. Treasury repurchases between banks.
cohu_CashPayoutOfPerformanceAwardsLimitationPerYear
Cash Payout of Performance Awards Limitation Per Year
Represents cash payout of performance awards limitation per year.
Long-Term Debt, Type [Axis]
Long-Term Debt, Type [Domain]
cohu_SharebasedCompensationArrangementBySharebasedPaymentAwardShareValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Share Value
Represents share value for share-based compensation arrangement by share-based payment award.
Inventory Charges [Member]
Related to inventory charges.
Integration Program [Member]
Related to the Integration program
cohu_AnnualLimitationOnCompensation
Annual Limitation on Compensation
Represents annual limit on compensation.
Profit (loss) for reportable segments
The amount of profit (loss) from operating segments.
Cash flows from investing activities:
us-gaap_ExtinguishmentOfDebtAmount
Extinguishment of Debt, Amount
us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable
Income taxes payable
Related Party Transactions Disclosure [Text Block]
Changes in other accrued liabilities
SWITZERLAND
SEC Schedule, 12-09, Reserve, Inventory [Member]
CHINA
us-gaap_IncreaseDecreaseInAccountsPayable
Accounts payable
GERMANY
us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax
Change in unrealized gain/loss on investments, tax
us-gaap_DebtInstrumentTerm
Debt Instrument, Term (Year)
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax
Total share-based compensation, net of tax
Share-based compensation of continuing operations
cohu_DeferredProfitLongterm
Deferred Profit Long-term
The carrying value of deferred revenue, net of expenses, as of the balance sheet date that is expected to be recognized as such after one year.
Long-term lease liabilities
Present value of lessee's discounted obligation for lease payments from operating and finance leases, classified as noncurrent.
us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent
Adjustments related to postretirement benefits, tax
Foreign currency translation adjustments, tax
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income
us-gaap_IncreaseDecreaseInContractWithCustomerLiability
Customer advances
Common stock, shares outstanding (in shares)
us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Debt Instrument, Basis Spread on Variable Rate
us-gaap_DebtInstrumentInterestRateStatedPercentage
Debt Instrument, Interest Rate, Stated Percentage
Variable lease expense
us-gaap_LeaseCost
Net lease cost
JAPAN
us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent
Operating leases
Operating leases
Short-term operating leases
Lease, Cost [Table Text Block]
Leased assets obtained in exchange for new finance lease liabilities
Leased assets obtained in exchange for new operating lease liabilities
us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1
Operating leases (Year)
us-gaap_DebtInstrumentFaceAmount
Debt Instrument, Face Amount
us-gaap_DebtInstrumentCollateralAmount
Debt Instrument, Collateral Amount
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Variable Rate [Domain]
Amortization of cloud-based software implementation costs
Capitalized Computer Software, Amortization
Variable Rate [Axis]
us-gaap_IncreaseDecreaseInAccountsReceivable
Accounts receivable
Share-based compensation expense
us-gaap_TreasuryStockValueAcquiredCostMethod
Common stock repurchases
us-gaap_TreasuryStockCommonValue
Treasury stock, at cost; 2,253 shares in 2023 and 1,767 shares in 2022
us-gaap_StockRepurchasedDuringPeriodShares
Stock Repurchased During Period, Shares (in shares)
us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
Repurchase and retirement of stock
PHILIPPINES
us-gaap_StockRepurchasedDuringPeriodValue
Stock Repurchased During Period, Value
us-gaap_IncreaseDecreaseInOtherCurrentAssets
Other current assets
us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
Changes in other assets
us-gaap_IncreaseDecreaseInInventories
Inventories
us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)
Net periodic costs
Service cost
Service cost
Interest cost
Interest cost
Interest cost
us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
Expected return on assets
us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)
SINGAPORE
us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Exercised, outstanding and exercisable (in shares)
Shares issued under ESPP
us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Line of Credit Facility, Maximum Borrowing Capacity
Exercise of stock options
Shares issued for restricted stock units vested
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)
us-gaap_StockIssuedDuringPeriodSharesNewIssues
Stock Issued During Period, Shares, New Issues (in shares)
us-gaap_LiabilitiesAndStockholdersEquity
Liabilities and Equity
UNITED STATES
Sale of common stock, net of issuance costs
Retained earnings
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Total accumulated other comprehensive loss
Money Market Funds [Member]
Debt Disclosure [Text Block]
Malaysian Ringgit Foreign Exchange Forward [Member]
Related to Malaysian Ringgit foreign exchange forward.
Cash and Cash Equivalents [Axis]
Cash and Cash Equivalents [Domain]
Underwritten Public Offering [Member]
Related to underwritten public offering.
Cash [Member]
Changes in current assets and liabilities, excluding effects from divestitures:
us-gaap_ForeignCurrencyTransactionGainLossRealized
Realized Gain (Loss), Foreign Currency Transaction, before Tax
us-gaap_OperatingLeaseLiabilityNoncurrent
Operating, noncurrent
Present value of lease liabilities, operating leases
us-gaap_OperatingLeaseLiabilityCurrent
Operating, current
us-gaap_FinanceLeaseLiabilityCurrent
Finance, current
us-gaap_FinanceLeaseLiabilityNoncurrent
Finance, noncurrent
Operating lease right of use assets
Operating lease assets
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Total lease payments, operating leases
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Less: Interest, operating leases
Present value of lease liabilities, finance leases
Financing cash flows from finance leases
Payments on current and long-term finance lease liabilities
us-gaap_DeferredIncomeTaxExpenseBenefit
Total deferred
Deferred income taxes
2026, operating leases
2027, operating leases
2028, operating leases
us-gaap_FinanceLeaseRightOfUseAsset
Finance lease assets
Thereafter, operating leases
us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax
Accumulated net adjustments related to postretirement benefits
2024, operating leases
2025, operating leases
us-gaap_PaymentsForRestructuring
Amounts paid or charged
us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax
Accumulated net currency translation adjustments
South Korean Won Forward Exchange Forward [Member]
Foreign exchange forward traded on an exchange for options or future contracts to buy or sell a South Korean Won, at a specified date, at a fixed exercise exchange rate.
us-gaap_ShareBasedCompensation
Share-based compensation expense
Amortization of debt discounts and issuance costs
us-gaap_AssetsFairValueDisclosure
Assets, Fair Value Disclosure
us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments
Net accretion on investments
us-gaap_Depreciation
Depreciation
Total depreciation and amortization
Depreciation and amortization
us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges
(Gain) loss from sale of property, plant and equipment
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Cash and cash equivalents
Treasury Stock, Shares (in shares)
Common stock, $1 par value; 90,000 shares authorized, 49,429 shares issued and outstanding in 2023 and 49,276 shares in 2022
Measurement Frequency [Axis]
Adjustments to reconcile net income to net cash provided by operating activities:
cohu_DefinedBenefitPlanHealthCareCostTrendRateAnnualRateOfChange
Defined Benefit Plan, Health Care Cost Trend Rate, Annual Rate of Change
The annual rate of change increase (decrease) in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.
Measurement Frequency [Domain]
Fair Value, Recurring [Member]
Common stock, shares authorized (in shares)
Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block]
Common stock, shares issued (in shares)
Certificates of Deposit [Member]
Common stock, par value (in dollars per share)
Statistical Measurement [Domain]
Operating cash flows from operating leases
Maximum [Member]
Minimum [Member]
Ownership [Domain]
Product and Service [Axis]
Product and Service [Domain]
Statistical Measurement [Axis]
Operating cash flows from finance leases
Ownership [Axis]
Preferred stock, $1 par value; 1,000 shares authorized, none issued
Preferred stock, shares issued (in shares)
Cash paid for interest
Geographical [Axis]
Property, Plant and Equipment [Table Text Block]
Geographical [Domain]
Preferred stock, shares authorized (in shares)
Preferred stock, par value (in dollars per share)
Fair Value, Inputs, Level 3 [Member]
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]
us-gaap_ProductWarrantyAccrualPayments
Warranty payments
Warranty accruals
Cash flows from operating activities:
Revenue [Policy Text Block]
Statement [Line Items]
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent [Member]
Paid-in capital
Schedule of Product Warranty Liability [Table Text Block]
Stockholders' equity:
MALAYSIA
Deferred income taxes
Long-term deferred income tax liabilities
Consolidation Items [Domain]
us-gaap_ContractWithCustomerLiability
Contract with Customer, Liability
Consolidation Items [Axis]
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Condensed Statement of Comprehensive Income [Table Text Block]
Disposal Group Classification [Axis]
Disposal Group Classification [Domain]
us-gaap_ProductWarrantyAccrual
Beginning balance
Ending balance
Retained Earnings [Member]
Treasury Stock, Common [Member]
us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Stock Repurchase Program, Remaining Authorized Repurchase Amount
Additional Paid-in Capital [Member]
Common Stock [Member]
us-gaap_StockRepurchaseProgramAuthorizedAmount1
Stock Repurchase Program, Authorized Amount
Non-current Other Accrued Liabilities [Member]
Represents non-current other accrued liabilities.
Equity Components [Axis]
Equity Component [Domain]
us-gaap_LongTermDebt
Long-Term Debt
Total
Lines of credit
Long-Term Line of Credit
us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
Less: financing fees and discount
Document Annual Report
Machinery and Equipment [Member]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Entity Incorporation, State or Country Code
Long term Debt
Long-Term Debt, Gross
Document Transition Report
Document Financial Statement Error Correction [Flag]
Foreign Currency Gain (Loss) [Member]
Selling, General and Administrative Expenses [Member]
Entity Interactive Data Current
Short-term borrowings
Security Exchange Name
Title of 12(b) Security
Cost of Sales [Member]
Research and Development Expense [Member]
us-gaap_ValuationAllowancesAndReservesBalance
Balance, end of year
Balance, beginning of year
us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense
Income Statement Location [Axis]
Income Statement Location [Domain]
cohu_IncreaseDecreaseInOperatingLeaseRightOfUseAssets
Operating lease right-of-use assets
Amount of increase (decrease) in operating lease right-of-use assetS.
Equity Incentive Plan 2005 [Member]
Information pertaining to the 2005 Equity Incentive Plan.
us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Subsidiary, Ownership Percentage, Noncontrolling Owner
Operating lease right-of-use assets
Amount of deferred tax liability attributable to taxable temporary differences from operating lease right-of-use assets.
Lease liabilities
Amount before allocation of valuation allowances of deferred tax asset attributable to lease liabilities.
Segments [Axis]
Segments [Domain]
cohu_IncreaseDecreaseOfNetIncomeDueToImpactOfTaxHolidays
Increase (Decrease) of Net Income Due to Impact of Tax Holidays
Increase (decrease) in net income due to the impact of tax holidays.
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]
Statement [Table]
Construction Loan [Member]
A borrowing arrangement which provides the entity constructing a facility (such as a building and a landfill) with funds to effect construction, generally on a draw down, or as needed, basis.
us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent
Other comprehensive loss, before tax
us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Reserve for excess and obsolete inventories not charged to expense PCB Test sale
us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1
Other comprehensive loss, tax
Income Statement [Abstract]
us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
Other comprehensive income (loss), net of tax
2026
First Facility [Member]
Represents the first facility.
2027
Disposal Group Name [Axis]
2028
us-gaap_RestructuringReserve
Accrued restructuring, balance
Accrued restructuring, balance
Disposal Group Name [Domain]
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
Thereafter
Second Facility [Member]
Represents the second facility.
Loan Facilities [Member]
Represents the loan facilities.
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
2025
cohu_IncreaseDecreaseInDeferredProfit
Deferred profit
The amount of increase (decrease) in deferred profit during the period.
Non-systems [Member]
The amount of revenue derived from all other sources that are not systems.
Systems [Member]
The amount of revenue derived from systems.
Inventory related charges
The adjustment related to the amortization of inventory step-up and inventory related charges.
Machinery, Equipment and Software [Member]
Tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment and collection of computer programs and related data that provide instructions to a computer.
Other Accrued Liabilities and Long-term Lease Liabilities [Member]
Primary financial statement caption encompassing other accrued liabilities and long-term lease liabilities.
cohu_InterestCapitalizedAssociatedWithCloudComputingImplementation
Interest capitalized associated with cloud computing implementation
Amount of interest capitalized associated with cloud computing implementation.
Employee Severance and Other Exit Costs [Member]
Represents employee severance and other exit costs.
Equiptest Engineering Pte Ltd. (“EQT”) [Member]
Represents Equiptest Engineering Pte Ltd. (“EQT”).
Change in unrealized gain/loss on investments, before tax
us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPortionAttributableToParent
Adjustments related to postretirement benefits, before tax
Accrued retirement benefits
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent
Foreign currency translation adjustments, before tax
Foreign Exchange Forward [Member]
us-gaap_StockholdersEquity
Total stockholders' equity
Balance
Balance
Noncurrent income tax liabilities
Position [Domain]
Long [Member]
us-gaap_LongTermDebtNoncurrent
Total long-term debt
Long-term debt
Position [Axis]
Gross unrealized losses
Gross unrealized gains
Amortized cost
Due after 1 year through 5 years, amortized cost
Due after 5 years through 10 years, amortized cost