Document And Entity Information
Foreign exchange forward contracts
Note To Financial Statement Details Textual
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Total
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
Due in one year or less, amortized cost
Significant Accounting Policies
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value, Total
Risk-free interest rate
Note 1 - Summary of Significant Accounting Policies
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
Due in one year or less, fair value
Note 2 - Goodwill and Purchased Intangible Assets
Xcerra Integration Program [Member]
Represents Xcerra Integration Program.
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Due after 1 year through 5 years, fair value
Note 3 - Borrowings and Credit Agreements
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 4 - Restructuring Charges
Liabilities, Noncurrent [Abstract]
Operating lease assets acquired from MCT
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 5 - Financial Instruments Measured at Fair Value
Financing lease assets acquired from MCT
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 6 - Employee Benefit Plans
Note 7 - Business Acquisitions
London Interbank Offered Rate (LIBOR) 1 [Member]
Interest rate at which a bank borrows funds from other banks in the London interbank market.
Note 8 - Derivative Financial Instruments
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
Note 10 - Income Taxes
Note 11 - Segment and Geographic Information
Expected volatility
Note 12 - Leases
us-gaap_LiabilitiesCurrent
Total current liabilities
Note 14 - Guarantees
Note 15 - Accumulated Other Comprehensive Income (Loss)
Other comprehensive income (loss), net of tax
Note 16 - Related Party Transactions
Note 1 - Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Details)
Asset-Backed Securities [Member]
Expected term (years) (Year)
Note 1 - Summary of Significant Accounting Policies - Inventories (Details)
Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details)
us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
Adjustments related to postretirement benefits
Note 1 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details)
us-gaap_DerivativePriceRiskOptionStrikePrice
Derivative, Price Risk Option Strike Price
Note 2 - Goodwill and Purchased Intangible Assets - Summary of Borrowings (Details)
Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details)
US States and Political Subdivisions Debt Securities [Member]
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)
Note 4 - Restructuring Charges - Charges (Details)
Debt Security, Government, Non-US [Member]
Swiss Plan [Member]
Information about the Swiss Plan.
Granted (in dollars per share)
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent
Foreign currency translation adjustments
Released (in dollars per share)
Note 5 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details)
Cancelled (in dollars per share)
US Treasury Securities [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Outstanding, beginning of year (in dollars per share)
Outstanding, end of year (in dollars per share)
Note 5 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details)
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Cancelled (in shares)
Note 5 - Financial Instruments Measured at Fair Value - Assets Measured at Fair Value on Recurring Basis (Details)
Foreign currency translation adjustments
us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
Changes in cumulative translation adjustment
us-gaap_DeferredCompensationLiabilityCurrent
Deferred Compensation Liability, Current
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Outstanding, beginning of year (in shares)
Outstanding, end of year (in shares)
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)
Schedule of Derivative Instruments [Table Text Block]
Note 6 - Employee Benefit Plans - Weighted-average Actuarial Assumptions to Determine Benefit Obligation and Net Periodic Benefit Cost (Details)
Real Estate Investments [Member]
This element represents direct equity investments in real estate projects
Derivative [Table]
Granted (in shares)
Note 6 - Employee Benefit Plans - Post-retirement Benefit Obligation to Funded Status and Liability (Details)
Corporate Debt Securities [Member]
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.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Released (in shares)
Note 6 - Employee Benefit Plans - Restricted Stock Unit Activity Under Share-based Compensation Plans (Details)
Note 6 - Employee Benefit Plans - Performance Based Stock Unit Activity Under Share-based Compensation Plans (Details)
Note 6 - Employee Benefit Plans - Weighted-average Assumptions Used to Value Share-based Awards Granted (Details)
us-gaap_LongTermDebtCurrent
Less: current portion
Note 6 - Employee Benefit Plans - Reported Share-based Compensation in Consolidated Financial Statements (Details)
Note 7 - Business Acquisitions - Purchase Price Allocation (Details)
Current installments of long-term debt
us-gaap_OtherComprehensiveIncomeLossTax
Other comprehensive income
Other comprehensive loss
us-gaap_OtherComprehensiveIncomeLossNetOfTax
Note 7 - Business Acquisitions - Preliminary Allocation of Intangible Assets (Details)
Note 8 - Derivative Financial Instruments - Locations and Amounts of Gains (Loss) (Details)
Note 8 - Derivative Financial Instruments - Foreign Currency Forward Contracts Outstanding (Details)
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Debt Securities, Available-for-Sale, Unrealized Loss Position
Note 10 - Income Taxes - Income before Income Taxes (Details)
Note 10 - Income Taxes - Income Tax Expense (Benefit) (Details)
Note 10 - Income Taxes - Income (Loss) Before Income Taxes From Continuing Operations (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number (in shares)
Note 10 - Income Taxes - Income Taxes Paid, Net (Details)
Note 10 - Income Taxes - Components of Deferred Tax Assets and Liabilities (Details)
us-gaap_LinesOfCreditCurrent
Revolving credit facility
Note 10 - Income Taxes - Reconciliation of Income Tax Computed at U.S. Federal Statutory Tax Rate to Provision (Benefit) (Details)
Weighted-average grant date fair value per share (in dollars per share)
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)
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)
Note 11 - Segment and Geographic Information - Summary of Property, Plant and Equipment and Other Long Lived Assets in Geographical Area (Details)
Note 12 - Leases - Future Minimum Lease Payments (Details)
Note 12 - Leases - Balance Sheet Information (Details)
Financial Instruments [Domain]
Note 12 - Leases - Lease Expense (Details)
Note 12 - Leases - Cash Flow Information (Details)
Note 14 - Guarantees - Changes in Accrued Warranty (Details)
Note 15 - Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Loss (Details)
Note 15 - 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)
Customer advances
Notes To Financial Statements
Financial Instrument [Axis]
Notes To Financial Statements [Abstract]
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.
Accrued compensation and benefits
Income taxes payable
Accounts payable
Unvested Restricted Stock Units [Member]
The unvested restricted stock units.
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
Plan Name [Axis]
Plan Name [Domain]
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)
Bureau of Internal Revenue, Philippines [Member]
Represents the Bureau of Internal Revenue of the Philippines.
Inland Revenue Board of Malaysia [Member]
Represents the Inland Revenue Board of Malaysia.
us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Income tax benefit
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
Award Type [Domain]
Award Type [Axis]
Accumulated Amortization
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
Property, plant and equipment, net
Property plant and equipment, net
Property, plant and equipment, net
cohu_CollectionTermRange
Collection Term Range (Year)
The collection term range.
Goodwill
Goodwill
Balance
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
Equiptest Engineering Pte Ltd. [Member]
Related to Equiptest Engineering Pte Ltd.
Rest of the World [Member]
The rest of the world.
Changes in accrued retiree medical benefits
Contract amount
us-gaap_DerivativeAssets
Derivative Instrument [Axis]
Derivative Contract [Domain]
Short term investment
us-gaap_AvailableForSaleSecuritiesDebtSecurities
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 from continuing operations
Income Tax Expense (Benefit)
Line of Credit [Member]
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_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Defined Contribution Plan, Employer Discretionary Contribution Amount
General & administrative
us-gaap_GeneralAndAdministrativeExpense
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
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
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.
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
dei_CityAreaCode
City Area Code
us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Defined Benefit Plan, Expected Future Benefit Payment, Year One
New Accounting Pronouncements, Policy [Policy Text Block]
us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year
us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal
Equity Method Investment, Realized Gain (Loss) on Disposal
us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate
us-gaap_GainLossOnSaleOfPropertyPlantEquipment
(Gain) loss from sale of property, plant and equipment
Rate of return on assets
us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease
Compensation increase
Compensation increase
Current Fiscal Year End Date
Discount rate
us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate
Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table]
Discount rate
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate
Accumulated benefit obligation at beginning of year
Accumulated benefit obligation at end of year
us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Valuation and Qualifying Accounts Disclosure [Table Text Block]
The tabular disclosure of valuation and qualifying accounts and reserves.
Document Fiscal Period Focus
Document Fiscal Year Focus
dei_DocumentPeriodEndDate
Document Period End Date
dei_EntityFileNumber
Entity File Number
dei_EntityEmergingGrowthCompany
Entity Emerging Growth Company
us-gaap_WriteOffOfDeferredDebtIssuanceCost
Deferred Debt Issuance Cost, Writeoff
dei_DocumentType
Document Type
Loss on extinguishment of debt
us-gaap_GainsLossesOnExtinguishmentOfDebt
Loss on extinguishment of debt
dei_EntitySmallBusiness
Entity Small Business
Return on assets, net of actuarial loss
dei_EntityShellCompany
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
dei_EntityPublicFloat
Entity Public Float
us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid
Benefits paid
dei_EntityFilerCategory
Entity Filer Category
dei_EntityCurrentReportingStatus
Entity Current Reporting Status
Restructuring charges
Restructuring Charges
dei_EntityVoluntaryFilers
Entity Voluntary Filers
us-gaap_BusinessCombinationAcquisitionRelatedCosts
Business Combination, Acquisition-Related Cost, Expense
dei_EntityWellKnownSeasonedIssuer
Entity Well-known Seasoned Issuer
us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant
Participant contributions
Award Timing Disclosures [Line Items]
Actuarial gain (loss)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)
Foreign currency exchange adjustment
Plan change
Settlements
us-gaap_DefinedBenefitPlanSettlementsBenefitObligation
Hedged derivative gain (loss)
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax
Award Timing MNPI Disclosure [Text Block]
us-gaap_GoodwillImpairmentLoss
Goodwill, Impairment Loss
Plan Curtailment
Net sales percentage
Statement of Comprehensive Income [Abstract]
ecd_AwardTmgMnpiCnsdrdFlag
Award Timing MNPI Considered [Flag]
Entity Tax Identification Number
Entity Central Index Key
Insider Trading Policies and Procedures [Line Items]
dei_EntityRegistrantName
Entity Registrant Name
Insider Trading Policies and Procedures Adopted [Flag]
Insider Trading Policies and Procedures Adopted [Flag]
Entity [Domain]
Customer Concentration Risk [Member]
Legal Entity [Axis]
Entity Address, Address Line One
Amortization of purchased intangible assets
Amortization of purchased intangible assets
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]
cohu_PolicyTable
ecd_TrdArrIndTitle
Trading Arrangement, Individual Title
ecd_TrdArrIndName
Trading Arrangement, Individual Name
ecd_TrdArrSecuritiesAggAvailAmt
Trading Arrangement, Securities Aggregate Available Amount (in shares)
dei_EntityCommonStockSharesOutstanding
Entity Common Stock, Shares Outstanding (in shares)
Trading Arrangements, by Individual [Table]
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]
dei_LocalPhoneNumber
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
Accounts Receivable, Credit Loss Expense (Reversal)
us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax
Raw materials and purchased parts
Selling
us-gaap_SellingExpense
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
Research and development
cohu_IncreaseDecreaseInAccruedCompensationWarrantyAndOtherLiabilities
Accrued compensation, warranty and other liabilities
The increase (decrease) during the period in accrued salaries, warranty, and other liabilities.
us-gaap_InterestExpense
Interest expense
Derivative Instruments, Gain (Loss) [Table Text Block]
us-gaap_InterestExpenseDebt
Interest Expense, Debt
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]
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
Defined Benefit Plan [Table]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
Finite-Lived Intangible Asset, Expected Amortization, after Year Five
us-gaap_DerivativeUnderlyingInvestmentShares
Derivative, Underlying Investment, Shares
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
Finite-Lived Intangible Asset, Expected Amortization, Year Two
Fair Value of Financial Instruments, Policy [Policy Text Block]
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
Finite-lived 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
FTZ [Member]
Fraes-und Technologiezentrum GmbH Frasdorf "FTZ", an investee of the legal entity.
Costs Associated with Exit or Disposal Activities or Restructurings, Policy [Policy Text Block]
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.
Taxes receivable
Advertising Cost [Policy Text Block]
Ismeca [Member]
Represents information pertaining to Ismeca, a wholly-owned subsidiary of Cohu.
Facilities in San Diego, California [Member]
Represents facilities in San Diego, California.
Poway Volume Manufacturing Transition [Member]
Represents Poway Volume Manufacturing Transition.
cohu_NumberOfAvailableLinesOfCredit
Number of Available Lines of Credit
Represents the number of available lines of credit as of the balance sheet date.
Tignis, Inc [Member]
Represents Tignis, Inc.
Standard Product Warranty, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsValuationAllowance
Less valuation allowance
Deferred Tax Assets, Valuation Allowance
Commitments and Contingencies, Policy [Policy Text Block]
Effective Cost of Funds (“ECOF”) [Member]
Represents Effective Cost of Funds (“ECOF”).
2025 Strategic Restructuring [Member]
Represents 2025 Strategic Restructuring.
us-gaap_DeferredTaxAssetsNet
Total deferred tax assets
Wholly Owned Subsidiary in Malaysia [Member]
Represents the wholly owned subsidiary in Malaysia.
cohu_DebtLongtermAndShorttermCombinedAmountGross
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]
us-gaap_DeferredTaxAssetsGross
Gross deferred tax assets
Other assets (long-term)
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]
us-gaap_DeferredIncomeTaxLiabilities
Total deferred tax liabilities
Inventories
Total inventories
Net sales
Net sales
Capitalized R&D
Foreign transaction 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]
Schedule of Segment Reporting Information, by Segment [Table]
Accrued employee benefits
us-gaap_NumberOfOperatingSegments
Number of Operating Segments
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]
Short-term investments
Land and Land Improvements [Member]
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]
Long-Lived Tangible Asset [Domain]
Tax credit carryforwards
Segment Reporting Disclosure [Text Block]
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]
Assets [Abstract]
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net decrease in cash and cash equivalents
Interest income
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash provided by (used in) financing activities
Effect of exchange rate changes on cash and cash equivalents
us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
Effect of exchange rate changes on cash and cash equivalents
us-gaap_OperatingIncomeLoss
Loss from operations
Other (expense) income:
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
us-gaap_DeferredTaxLiabilitiesOther
Other
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash provided by (used in) investing activities
us-gaap_DeferredTaxLiabilities
Net deferred tax liabilities
Derivatives, Policy [Policy Text Block]
Unremitted earnings of foreign subsidiaries
Concentration Risk, Credit Risk, Policy [Policy Text Block]
us-gaap_GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNet
Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Net
us-gaap_CostDepreciationAmortizationAndDepletion
Cost, Depreciation, Amortization and Depletion
us-gaap_CostsAndExpenses
Costs and Expenses
Cost and expenses:
us-gaap_PaymentsForRepurchaseOfCommonStock
Acquisition of treasury stock
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.
U.S. State
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
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]
Tax on Global Intangible Low-Taxed Income (GILTI)
us-gaap_RevenueRemainingPerformanceObligation
Revenue, Remaining Performance Obligation, Amount
Tax on Global Intangible Low-Taxed Income (GILTI), percent
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.
Leases, Balance Sheet Information [Table Text Block]
Tabular disclosure of balance sheet information for leases.
2027, 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
Income (loss) before taxes
State Administration of Taxation, China [Member]
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.
National Tax Agency, Japan [Member]
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.
2030, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fifth fiscal year following latest fiscal year.
2029, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fourth fiscal year following latest fiscal year.
us-gaap_PaymentsForDerivativeInstrumentFinancingActivities
Purchase of capped calls related to convertible notes
Payments for Derivative Instrument, Financing Activities
2028, 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.
dei_IcfrAuditorAttestationFlag
ICFR Auditor Attestation Flag
cohu_LesseeLeaseLiabilityPaymentsDue
Total lease payments, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease.
Swiss Federal Tax Administration (FTA) [Member]
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.
us-gaap_PaymentsOfDebtIssuanceCosts
Payment of debt issuance costs
Federal Ministry of Finance, Germany [Member]
Inland Revenue, Singapore (IRAS) [Member]
State and Local Jurisdiction [Member]
Income Tax Authority, Name [Axis]
Income Tax Authority, Name [Domain]
Income Tax Jurisdiction [Axis]
Income Tax Jurisdiction [Domain]
Disaggregation of Revenue [Table Text Block]
Domestic Tax Jurisdiction [Member]
Foreign Tax Jurisdiction [Member]
us-gaap_RepaymentsOfLongTermDebt
Repayments of long-term debt
Repayments of Long-Term Debt
Cash and Cash Equivalents, Policy [Policy Text Block]
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Represents a business acquired by the reporting entity.
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.
us-gaap_OpenTaxYear
Open Tax Year
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
us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities
Reductions due to settlements
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.
dei_AuditorName
Auditor Name
dei_AuditorFirmId
Auditor Firm ID
dei_AuditorLocation
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_SharePrice
Share Price
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)
us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Diluted (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Blackrock [Member]
Represents the entity of Blackrock, a related party of the company.
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Proceeds from revolving line of credit, revolving credit facility and convertible notes
Proceeds from Lines of Credit
cohu_PurchaseOfCappedCalls
Purchase of capped calls
Purchase of Capped Calls
Equity impact of the value of capped calls purchased during the period.
Statement of Financial Position [Abstract]
us-gaap_EarningsPerShareDiluted
Diluted (in dollars per share)
Weighted average common shares outstanding (in shares)
Basic (in shares)
Tax on Subpart F Income, percent
Percentage of reported income tax expense from difference to expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to Subpart F income.
Tax on Subpart F Income
Amount of reported income tax expense from difference to expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to Subpart F Income.
us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments
Other, percent
Cost of sales
Cost of sales
FX of net investment hedge, percent
Percentage 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 FX of net investment hedges.
us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent
Other, percent
FX of net investment hedge
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 FX of net investment hedges.
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Income tax expense, percent
Vesting Over Three Year Period [Member]
Represents awards that vest over a three year period.
us-gaap_EarningsPerShareBasic
Basic (in dollars per share)
Business Combination [Axis]
Business Combination [Domain]
Change in valuation allowance, percent
Income Taxes Paid [Table Text Block]
Tabular disclosure of income taxes paid.
us-gaap_EffectiveIncomeTaxRateReconciliationTaxHolidays
Local country tax holiday, percent
Statement of Cash Flows [Abstract]
Warranty liability transferred
Represents warrant liability transferred for product warranty accrual.
Withholding taxes, percent
Local income taxes
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 foreign local income taxes.
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]
Statement of Stockholders' Equity [Abstract]
us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
Business Combination, Contingent Consideration, Range of Outcomes, Maximum, Amount
Other Foreign Jurisdictions [Member]
Represents other foreign jurisdictions.
Lease Contractual Term [Domain]
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]
Lease Contractual Term [Axis]
Local income taxes, percent
Percentage 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 applicable to foreign local income taxes.
Changes in unrecognized tax benefits, percent
Net issuance (repurchases) of stock, including awards settled in cash
Represents net issuance (repurchase) of stock, including awards settled in cash.
us-gaap_ProceedsFromIssuanceOfDebt
Proceeds from Issuance of Debt
us-gaap_RestructuringReserveTranslationAdjustment
Impact of currency exchange
Interest on lease liabilities
us-gaap_FinanceLeaseLiabilityPaymentsDue
Total lease payments, finance leases
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
us-gaap_RestructuringAndRelatedCostExpectedCost1
Restructuring and Related Cost, Expected Cost
Amortization of leased assets
2030, finance leases
Investments Classified by Contractual Maturity Date [Table Text Block]
Thereafter, finance leases
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther
Other, nondeductible, percent
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount
Less: Interest, finance leases
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
2026, finance leases
2027, finance leases
2028, finance leases
Unrealized Gain (Loss) on Investments [Table Text Block]
Equity based employee compensation, percent
2029, finance leases
Restructuring Plan [Axis]
Restructuring Plan [Domain]
Other Restructuring [Member]
srt_StockRepurchaseProgramAuthorizedAmount1
Share Repurchase Program, Authorized, Amount
Type of Restructuring [Domain]
Reversal of previously recognized unborn foreign tax credits, percent
us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent
Finance leases
Employee Severance [Member]
Restructuring and Related Activities Disclosure [Text Block]
State and local income taxes, net of federal income tax effect, percent
Foreign rate differential, percent
Restructuring and Related Costs [Table Text Block]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
Restructuring Type [Axis]
us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch
Research and development credits, percent
us-gaap_IncomeTaxReconciliationOtherAdjustments
Other
Cash flows from financing activities:
Other, net
Other
Tax provision at U.S. Federal statutory rate, percent
Change in valuation allowance
us-gaap_IncomeTaxReconciliationTaxHolidays
Local country tax holiday
Withholding taxes
us-gaap_PaymentsForProceedsFromHedgeInvestingActivities
Settlement of net investment hedge
Changes in unrecognized tax benefits
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
cohu_RestructuringChargesExcludingCostOfGoodsSold
Restructuring Charges, Excluding Cost of Goods Sold
Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes costs of goods sold.
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Liabilities assumed
Liabilities assumed
us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Payment for purchase of business, net of cash received
Payments to Acquire Businesses, Net of Cash Acquired
us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther
Other. nondeductible
Class of Stock [Axis]
us-gaap_CashAcquiredFromAcquisition
Cash Acquired from Acquisition
Equity based employee 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
Reversal of previously recognized unborn foreign tax credits
State and local income taxes, net of federal income tax effect
Foreign rate differential
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Property, plant and equipment
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets
Other assets
us-gaap_IncomeTaxReconciliationTaxCreditsResearch
Research and development credits
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles
Intangible assets
Tax provision at U.S. Federal statutory rate
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets
Current assets, including cash received
Hedging Relationship [Domain]
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.
Net Investment Hedging [Member]
Not Designated as Hedging Instrument [Member]
Hedging Relationship [Axis]
Income Tax Disclosure [Text Block]
Hedging Designation [Axis]
Hedging Designation [Domain]
Designated as Hedging Instrument [Member]
Schedule of Maturities of Long-Term Debt [Table Text Block]
Schedule of Debt [Table Text Block]
ecd_TrdArrExpirationDate
Trading Arrangement Expiration Date
Accumulated Other Comprehensive Income (Loss) [Table]
us-gaap_BusinessCombinationConsiderationTransferred1
Business Combination, Consideration Transferred
Inventory capitalized as capital assets
Represents information about inventory capitalized as property, plant and equipment.
Finite-lived intangible assets, estimated fair value
Finite-lived intangible assets, estimated fair value
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
Finite-lived intangible assets, average useful life (Year)
Finite-lived intangible assets, average useful life (Year)
cohu_StockRepurchaseProgramAdditionalAuthorizedAmount
Stock Repurchase Program, Additional Authorized Amount
Amount of additional stock repurchase plan authorized.
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.
Schedule of Nonvested Performance-Based Units Activity [Table Text Block]
Guarantees [Text Block]
Schedule of Net Benefit Costs [Table Text Block]
Schedule of Net Funded Status [Table Text Block]
cohu_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour
Lessee, Operating Lease, Liability, to be Paid, after Year Four
Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).
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.
us-gaap_PaymentsToAcquireShortTermInvestments
Purchases of short-term investments
2026, total
Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in next fiscal year following latest fiscal year.
Employee Stock Purchase Plan [Member]
Employee stock purchase plan.
Retirement Plan Name [Axis]
Retirement Plan Name [Domain]
Goodwill and Intangible Assets Disclosure [Text Block]
Schedule of Goodwill [Table Text Block]
Goodwill [Table]
Net cash received from sale of assets
Revolving Credit Facility [Member]
Postretirement Health Coverage [Member]
Retirement Plan Type [Axis]
Property, plant and equipment purchases included in accounts payable
Retirement Plan Type [Domain]
Credit Facility [Axis]
Credit Facility [Domain]
Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block]
Trademarks and Trade Names [Member]
Trade Names [Member]
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
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 (loss) per share:
Cash paid for income taxes, net of refunds
Cash paid for income taxes, net of refunds
Noncompete Agreements [Member]
Developed Technology Rights [Member]
Current and long-term operating lease liabilities
Supplemental disclosure of cash flow information:Cash Flow Information [Abstract]
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
Customer Relationships [Member]
us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Business Combination, Intangible Asset, Acquired, Finite-Lived [Table Text Block]
Effective Income Tax Rate Reconciliation [Table]
Net income (loss)
Net income (loss)
Net income
Restricted Stock Units (RSUs) [Member]
cohu_ConvertibleDebtInstrumentConversionRateNumberOfSharesPer1000PrincipalAmount
Convertible Debt Instrument, Conversion Rate, Number of Shares Per $1,000 Principal Amount
The number of shares convertible per $1,000 principal amount under a convertible debt instrument.
cohu_DebtInstrumentOptionToPurchaseAdditionalPrincipal
Debt Instrument, Option to Purchase Additional Principal
The option to purchase additional principal of a debt instrument.
Capped Call Transaction [Member]
Related to capped call transaction.
cohu_ConvertibleDebtInstrumentConversionPremiumPercent
Convertible Debt Instrument, Conversion Premium, Percent
The percent conversion premium for a convertible debt instrument.
Performance Shares [Member]
Convertible Senior Notes Due 2031 [Member]
Related to convertible senior notes due 2031
us-gaap_InterestExpenseDebtExcludingAmortization
Interest Expense, Debt, Excluding Amortization
Share-Based Payment Arrangement, Option [Member]
Impact of currency exchange
us-gaap_GoodwillForeignCurrencyTranslationGainLoss
Additions
us-gaap_GoodwillAcquiredDuringPeriod
cohu_DerivativeInstrumentCapPrice
Derivative Instrument, Cap Price
The cap price for a derivative instrument.
Business Combination [Table]
Long-Term Debt, Type [Axis]
Long-Term Debt, Type [Domain]
Inventory Charges [Member]
Related to inventory charges.
Cash flows from investing activities:
Income (loss) per share:
us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable
Income taxes payable
Related Party Transaction [Table]
Changes in other accrued liabilities
Related Party Transactions Disclosure [Text Block]
SEC Schedule, 12-09, Reserve, Inventory [Member]
CHINA
us-gaap_IncreaseDecreaseInAccountsPayable
Accounts payable
GERMANY
us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax
Change in unrealized gain/loss on investments
us-gaap_DebtInstrumentTerm
Debt Instrument, Term
us-gaap_DebtInstrumentConvertibleConversionPrice1
Debt Instrument, Convertible, Conversion Price
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax
Total share-based compensation, net of tax
Stock-based compensation
Share-based compensation of continuing operations
us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger
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
Foreign currency translation adjustments
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income (loss)
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
us-gaap_DebtInstrumentInterestRateEffectivePercentage
Debt Instrument, Interest Rate, Effective Percentage
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
The 2025 Strategic Restructuring [Member]
Relating to the 2025 strategic restructuring.
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Variable Rate [Domain]
Amortization of cloud-based software implementation costs
Capitalized Computer Software, Amortization
Schedule of Long-Term Debt Instruments [Table]
Share-based compensation expense
us-gaap_IncreaseDecreaseInAccountsReceivable
Accounts receivable, net
Repurchase and retirement of stock
us-gaap_TreasuryStockValueAcquiredParValueMethod
Common stock repurchases
us-gaap_TreasuryStockCommonValue
Treasury stock, at cost; 3,030 shares in 2025 and 2,891 shares in 2024
us-gaap_StockRepurchasedDuringPeriodShares
Stock Repurchased During Period, 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
Net periodic costs
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)
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
Shares issued under ESPP
Pension curtailment gain
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment
Curtailment
us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Line of Credit Facility, Maximum Borrowing Capacity
Shares issued for restricted stock units vested
Secured Overnight Financing Rate (SOFR) [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)
TAIWAN
Other segment items
us-gaap_SegmentReportingOtherItemAmount
us-gaap_LiabilitiesAndStockholdersEquity
Liabilities and Equity
UNITED STATES
Retained earnings
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Money Market Funds [Member]
Japanese Yen Foreign Exchange Forward [Member]
Related to Japanese Yen foreign exchange forward.
Debt Disclosure [Text Block]
Cash and Cash Equivalents [Axis]
Cash and Cash Equivalents [Domain]
Cash [Member]
Changes in current assets and liabilities:
us-gaap_ForeignCurrencyTransactionGainLossRealized
Realized Gain (Loss), Foreign Currency Transaction, before Tax
us-gaap_OperatingLeaseLiabilityNoncurrent
Operating
us-gaap_OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]
Present value of lease liabilities, operating leases
Operating
us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]
us-gaap_FinanceLeaseLiabilityCurrent
Finance
us-gaap_FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]
us-gaap_FinanceLeaseLiabilityNoncurrent
Finance
us-gaap_FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]
Operating lease right of use assets
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Total lease payments, operating leases
Lessee, Operating Lease, Liability, to be Paid
us-gaap_OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]
Financing cash flows from finance leases
Payments on finance lease liabilities
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Less: Interest, operating leases
Present value of lease liabilities, finance leases
us-gaap_DeferredIncomeTaxExpenseBenefit
Deferred income taxes
Total deferred
2028, operating leases
Lessee, Operating Lease, Liability, to be Paid, Year Three
2029, operating leases
Lessee, Operating Lease, Liability, to be Paid, Year Four
2030, operating leases
us-gaap_FinanceLeaseRightOfUseAsset
Finance lease assets
Thereafter, operating leases
us-gaap_FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]
2026, operating leases
Lessee, Operating Lease, Liability, to be Paid, Year One
2027, operating leases
Lessee, Operating Lease, Liability, to be Paid, Year Two
us-gaap_PaymentsForRestructuring
Amounts paid or charged
Withholding and other foreign taxes, net of foreign tax credit
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 withholding and other foreign taxes.
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
Pension curtailment gain
us-gaap_PensionExpenseReversalOfExpenseNoncash
Amortization of debt discounts and issuance costs
us-gaap_AmortizationOfDebtDiscountPremium
Amortization of Debt Discount (Premium)
us-gaap_AssetsFairValueDisclosure
Assets, Fair Value Disclosure
us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments
Net accretion on investments
us-gaap_Depreciation
Depreciation
us-gaap_DepreciationDepletionAndAmortization
Depreciation and amortization
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Cash and cash equivalents
Fair Value Measurement Inputs and Valuation Techniques [Table]
Treasury Stock, Common, Shares (in shares)
Change in fair value of contingent consideration liability
Common stock, $1 par value; 90,000 shares authorized, 49,875 shares issued and outstanding in 2025 and 49,601 shares in 2024
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Measurement Frequency [Axis]
Measurement Frequency [Domain]
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.
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 or Stated Value Per Share (in dollars per share)
Statistical Measurement [Domain]
Lessee, Lease, Description [Table]
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
Investment, Name [Domain]
Preferred stock, $1 par value; 1,000 shares authorized, none issued
Ownership [Axis]
Preferred Stock, Shares Issued (in shares)
Cash paid for interest
Investment, Name [Axis]
Geographical [Axis]
Geographical [Domain]
Property, Plant and Equipment [Table Text Block]
Preferred Stock, Shares Authorized (in shares)
Preferred Stock, Par or Stated Value Per Share (in dollars per share)
Fair Value, Inputs, Level 3 [Member]
Fair Value Hierarchy and NAV [Domain]
Customer [Axis]
Fair Value, Inputs, Level 1 [Member]
Customer [Domain]
Fair Value, Inputs, Level 2 [Member]
Fair Value Hierarchy and NAV [Axis]
us-gaap_ProductWarrantyAccrualPayments
Warranty payments
Warranty expense 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]
Paid-in capital
AOCI Attributable to Parent [Member]
Stockholders’ equity:
Schedule of Product Warranty Liability [Table Text Block]
Semiconductor Test & Inspection Segment [Member]
The Semiconductor Test & Inspection segment.
MALAYSIA
cohu_IncomeTaxExpenseBenefitAndOtherComprehensiveIncomeLossTax
Total
The total amount of income tax expense (benefit) and other comprehensive income (loss) tax.
Deferred income taxes
Long-term deferred income tax liabilities
us-gaap_ContractWithCustomerLiability
Contract with Customer, Liability
us-gaap_DerivativeLiabilities
Contract amount
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Impairment charge related to equity investment
Equity Method Investment, Other-than-Temporary Impairment
Consolidated Entities [Axis]
Consolidated Entities [Domain]
Condensed Statement of Comprehensive Income [Table Text Block]
us-gaap_ProductWarrantyAccrual
Balance at beginning of period
Balance at end of period
Schedule of Income Tax By Source [Table Text Block]
Tabular disclosure of income tax by source of income.
Retained Earnings [Member]
Treasury Stock, Common [Member]
us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Share Repurchase Program, Remaining Authorized, Amount
Additional Paid-in Capital [Member]
Common Stock [Member]
Non-current Other Accrued Liabilities [Member]
Represents non-current other accrued liabilities.
Equity Components [Axis]
Equity Component [Domain]
us-gaap_LongTermDebt
Total
Long-Term Debt
Stock, Class of Stock [Table]
Other Noncurrent Assets [Member]
us-gaap_LineOfCredit
Lines of credit
us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
Less: financing fees and discount
Document Annual Report
Machinery and Equipment [Member]
Statement of Financial Position Location, Balance [Axis]
Statement of Financial Position Location, Balance [Domain]
us-gaap_DebtInstrumentUnamortizedDiscount
Debt Instrument, Unamortized Discount
Entity Incorporation, State or Country Code
us-gaap_DebtInstrumentCarryingAmount
Long term Debt
Document Transition Report
dei_DocumentFinStmtErrorCorrectionFlag
Document Financial Statement Error Correction [Flag]
Selling, General and Administrative Expenses [Member]
dei_EntityInteractiveDataCurrent
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, beginning of year
Balance, end of year
us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense
Statement of Income Location, Balance [Axis]
Statement of Income Location, Balance [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.
Operating lease right-of-use assets
Amount of deferred tax liability attributable to taxable temporary differences from operating lease right-of-use assets.
us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Subsidiary, Ownership Percentage, Noncontrolling Owner
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.
Statement [Table]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [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
us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1
Other comprehensive loss
Income Statement [Abstract]
us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
Other comprehensive income (loss), net of tax
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
2028
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
2029
First Facility [Member]
Represents the first facility.
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
2030
us-gaap_RestructuringReserve
Restructuring Reserve
Accrued restructuring, balance
Accrued restructuring, balance
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
Thereafter
us-gaap_BusinessCombinationContingentConsiderationLiability
Business Combination, Contingent Consideration, Liability
Second Facility [Member]
Represents the second facility.
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
2026
Loan Facilities [Member]
Represents the loan facilities.
us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
2027
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.
Employee Severance and Other Exit Costs [Member]
Represents employee severance and other exit costs.
Accounting Standards Update and Change in Accounting Principle [Table]
Equiptest Engineering Pte Ltd. (“EQT”) [Member]
Represents Equiptest Engineering Pte Ltd. (“EQT”).
Other Commitments [Table]
Change in unrealized gain/loss on investments
us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPortionAttributableToParent
Adjustments related to postretirement benefits
Accrued retirement benefits
us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent
Foreign currency translation adjustments
us-gaap_StockholdersEquity
Total stockholders’ equity
Total accumulated other comprehensive loss
Balance
Balance
Foreign Exchange Forward [Member]
Noncurrent income tax liabilities
Position [Domain]
Long [Member]
Short [Member]
us-gaap_LongTermDebtNoncurrent
Total long-term debt
Long-term debt
Position [Axis]
Gross unrealized losses
Gross unrealized gains
Amortized cost
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
Due after 1 year through 5 years, amortized cost