$COHU
COHU INC Stock $cohu

$cohu Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-K Financial Statement

#000143774922003768 Filed on February 18, 2022

Income Statement

Concept	2021 Q4	2021	2020 Q4
Revenue	$191.9M	$887.2M	$202.4M
YoY Change	-5.19%	39.5%	42.49%
Cost Of Revenue	$107.5M	$500.3M	$111.1M
YoY Change	-3.28%	37.35%	26.36%
Gross Profit	$84.39M	$387.0M	$91.24M
YoY Change	-7.5%	42.38%	68.73%
Gross Profit Margin	43.99%	43.62%	45.09%
Selling, General & Admin	$31.12M	$127.0M	$33.60M
YoY Change	-7.37%	-1.77%	-2.61%
% of Gross Profit	36.88%	32.81%	36.83%
Research & Development	$22.60M	$91.96M	$22.80M
YoY Change	-0.89%	6.75%	9.62%
% of Gross Profit	26.77%	23.77%	24.99%
Depreciation & Amortization	$11.47M	$48.57M	$13.47M
YoY Change	-14.88%	-7.92%	-0.37%
% of Gross Profit	13.59%	12.55%	14.76%
Operating Expenses	$61.97M	$218.9M	$66.30M
YoY Change	-6.54%	1.64%	2.0%
Operating Profit	$22.43M	$201.5M	$24.94M
YoY Change	-10.07%	6081.53%	-328.29%
Interest Expense	-$273.0K	$6.413M	-$3.500M
YoY Change	-92.2%	-53.39%	-40.68%
% of Operating Profit	-1.22%	3.18%	-14.03%
Other Income/Expense, Net
YoY Change
Pretax Income	$17.28M	$192.3M	$15.30M
YoY Change	12.95%	-1559.69%	-178.46%
Income Tax	-$3.607M	$25.02M	$400.0K
% Of Pretax Income	-20.87%	13.01%	2.61%
Net Earnings	$20.89M	$167.3M	$14.86M
YoY Change	40.56%	-1312.41%	-186.07%
Net Earnings / Revenue	10.89%	18.86%	7.34%
Basic Earnings Per Share		$3.53	$0.35
Diluted Earnings Per Share	$422.6K	$3.45	$0.34
COMMON SHARES
Basic Shares Outstanding	48.69M	47.41M	41.97M
Diluted Shares Outstanding		48.46M

Balance Sheet

Concept	2021 Q4	2021	2020 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$379.9M	$379.9M	$170.0M
YoY Change	123.47%	123.47%	8.9%
Cash & Equivalents	$290.2M	$290.2M	$149.4M
Short-Term Investments	$89.70M	$89.70M	$20.70M
Other Short-Term Assets	$768.0K	$16.96M	$1.827M
YoY Change	-57.96%	-17.66%	-42.15%
Inventory	$161.1M	$161.1M	$142.5M
Prepaid Expenses	$16.19M		$18.77M
Receivables	$192.9M	$192.9M	$151.9M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$750.8M	$750.8M	$485.0M
YoY Change	54.79%	54.8%	10.31%
LONG-TERM ASSETS
Property, Plant & Equipment	$63.96M	$89.02M	$66.92M
YoY Change	-4.42%	-7.37%	-5.64%
Goodwill	$219.8M		$252.3M
YoY Change	-12.89%		5.71%
Intangibles	$177.3M		$233.7M
YoY Change	-24.12%		-15.03%
Long-Term Investments
YoY Change
Other Assets	$22.12M	$22.12M	$23.19M
YoY Change	-4.61%	-4.64%	15.79%
Total Long-Term Assets	$508.3M	$508.3M	$605.3M
YoY Change	-16.03%	-16.03%	-5.13%
TOTAL ASSETS
Total Short-Term Assets	$750.8M	$750.8M	$485.0M
Total Long-Term Assets	$508.3M	$508.3M	$605.3M
Total Assets	$1.259B	$1.259B	$1.090B
YoY Change	15.47%	15.48%	1.17%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$85.23M	$85.23M	$67.92M
YoY Change	25.48%	25.52%	39.48%
Accrued Expenses	$65.28M	$65.28M	$71.00M
YoY Change	-8.05%	-8.05%	-10.13%
Deferred Revenue	$7.300M		$14.41M
YoY Change	-49.34%		18.5%
Short-Term Debt	$3.059M	$3.059M	$5.300M
YoY Change	-42.28%	-42.28%	65.63%
Long-Term Debt Due	$14.40M	$11.51M	$8.389M
YoY Change	71.62%	248.64%	28.72%
Total Short-Term Liabilities	$192.5M	$192.5M	$174.5M
YoY Change	10.32%	10.29%	17.17%
LONG-TERM LIABILITIES
Long-Term Debt	$103.4M	$103.5M	$311.6M
YoY Change	-66.81%	-66.82%	-10.09%
Other Long-Term Liabilities	$54.74M	$54.74M	$63.00M
YoY Change	-13.11%	-13.11%	-7.22%
Total Long-Term Liabilities	$103.4M	$158.2M	$311.6M
YoY Change	-66.81%	-57.79%	-10.09%
TOTAL LIABILITIES
Total Short-Term Liabilities	$192.5M	$192.5M	$174.5M
Total Long-Term Liabilities	$103.4M	$158.2M	$311.6M
Total Liabilities	$295.9M	$376.5M	$486.0M
YoY Change	-39.13%	-34.87%	-1.9%
SHAREHOLDERS EQUITY
Retained Earnings	$193.6M		$26.23M
YoY Change	637.91%		-38.31%
Common Stock	$723.5M		$490.4M
YoY Change	47.54%		3.33%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$7.324M		$0.00
YoY Change
Treasury Stock Shares	$207.0K		$0.00
Shareholders Equity	$882.5M	$882.5M	$512.3M
YoY Change
Total Liabilities & Shareholders Equity	$1.259B	$1.259B	$1.090B
YoY Change	15.47%	15.48%	1.17%

Cashflow Statement

Concept	2021 Q4	2021	2020 Q4
OPERATING ACTIVITIES
Net Income	$20.89M	$167.3M	$14.86M
YoY Change	40.56%	-1312.41%	-186.07%
Depreciation, Depletion And Amortization	$11.47M	$48.57M	$13.47M
YoY Change	-14.88%	-7.92%	-0.37%
Cash From Operating Activities	$27.77M	$97.73M	$21.71M
YoY Change	27.9%	96.5%	56.98%
INVESTING ACTIVITIES
Capital Expenditures	-$3.076M	$12.00M	-$5.100M
YoY Change	-39.69%	-35.69%	9.68%
Acquisitions
YoY Change
Other Investing Activities	-$13.75M	$51.89M	-$19.66M
YoY Change	-30.07%	17197.67%	27985.71%
Cash From Investing Activities	-$16.82M	$39.89M	-$24.76M
YoY Change	-32.05%	-317.25%	424.58%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		-$215.8M
YoY Change
Debt Paid & Issued, Net		$206.1M
YoY Change		401.92%
Cash From Financing Activities	-5.999M	$6.712M	-18.51M
YoY Change	-67.59%	-117.63%	-6955.56%
NET CHANGE
Cash From Operating Activities	27.77M	$97.73M	21.71M
Cash From Investing Activities	-16.82M	$39.89M	-24.76M
Cash From Financing Activities	-5.999M	$6.712M	-18.51M
Net Change In Cash	4.945M	$140.8M	-21.56M
YoY Change	-122.94%	-2243.08%	-329.85%
FREE CASH FLOW
Cash From Operating Activities	$27.77M	$97.73M	$21.71M
Capital Expenditures	-$3.076M	$12.00M	-$5.100M
Free Cash Flow	$30.84M	$85.73M	$26.81M
YoY Change	15.05%	175.89%	45.08%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2021Q4	us-gaap	Inventory Net InventoryNet	161053000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	142500000	USD
CY2021Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	16194000	USD
CY2020Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	18773000	USD
CY2021Q4	us-gaap	Other Assets Current OtherAssetsCurrent	768000	USD
CY2020Q4	us-gaap	Other Assets Current OtherAssetsCurrent	1827000	USD
CY2021Q4	us-gaap	Assets Current AssetsCurrent	750793000	USD
CY2020Q4	us-gaap	Assets Current AssetsCurrent	485046000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	63957000	USD
CY2021	dei	Auditor Location AuditorLocation	San Diego, California
CY2021Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1
CY2020Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1
CY2021Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	1000000
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	1000000
CY2021Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2021Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2021Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	60000000
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	60000000
CY2021Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	48756000
CY2021Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	48756000
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	42190000
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	42190000
CY2021Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	207000
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	0
CY2020Q4	us-gaap	Capitalized Computer Software Gross CapitalizedComputerSoftwareGross	13500000	USD
CY2021	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	pure
CY2021	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	pure
CY2021Q2	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	pure
CY2020	us-gaap	Foreign Currency Transaction Gain Loss Realized ForeignCurrencyTransactionGainLossRealized	-3200000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	9.44
CY2019	cohu	Unrecognized Tax Benefits Interest Expense Net Of Accrued Interest Reversed UnrecognizedTaxBenefitsInterestExpenseNetOfAccruedInterestReversed	-300000	USD
CY2020Q4	us-gaap	Finance Lease Right Of Use Asset Accumulated Amortization FinanceLeaseRightOfUseAssetAccumulatedAmortization	100000	USD
CY2020Q4	us-gaap	Lessor Operating Lease Payments To Be Received Two Years LessorOperatingLeasePaymentsToBeReceivedTwoYears	100000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Next Twelve Months LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths	100000	USD
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	290201000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	149358000	USD
CY2021Q4	us-gaap	Short Term Investments ShortTermInvestments	89704000	USD
CY2020Q4	us-gaap	Short Term Investments ShortTermInvestments	20669000	USD
CY2021Q4	us-gaap	Accounts And Other Receivables Net Current AccountsAndOtherReceivablesNetCurrent	192873000	USD
CY2020Q4	us-gaap	Accounts And Other Receivables Net Current AccountsAndOtherReceivablesNetCurrent	151919000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	66916000	USD
CY2021Q4	us-gaap	Goodwill Goodwill	219791000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	252304000	USD
CY2021Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	177320000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	233685000	USD
CY2021Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	22123000	USD
CY2020Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	23192000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	25060000	USD
CY2020Q4	us-gaap	Long Term Loans From Bank LongTermLoansFromBank	311551000	USD
CY2021Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1259044000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	29203000	USD
CY2021Q4	us-gaap	Assets Assets	1259044000	USD
CY2020Q4	us-gaap	Assets Assets	1090346000	USD
CY2021Q4	us-gaap	Short Term Bank Loans And Notes Payable ShortTermBankLoansAndNotesPayable	3059000	USD
CY2020Q4	us-gaap	Short Term Bank Loans And Notes Payable ShortTermBankLoansAndNotesPayable	5314000	USD
CY2021Q4	us-gaap	Loans Payable To Bank Current LoansPayableToBankCurrent	11338000	USD
CY2020Q4	us-gaap	Loans Payable To Bank Current LoansPayableToBankCurrent	3075000	USD
CY2021Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	85230000	USD
CY2020Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	67923000	USD
CY2021Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	7300000	USD
CY2020Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	14410000	USD
CY2021Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	39835000	USD
CY2020Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	34862000	USD
CY2021Q4	us-gaap	Product Warranty Accrual Classified Current ProductWarrantyAccrualClassifiedCurrent	6614000	USD
CY2020Q4	us-gaap	Product Warranty Accrual Classified Current ProductWarrantyAccrualClassifiedCurrent	6066000	USD
CY2021Q4	cohu	Deferred Profit DeferredProfit	13208000	USD
CY2020Q4	cohu	Deferred Profit DeferredProfit	8671000	USD
CY2021Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	6873000	USD
CY2020Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	3857000	USD
CY2021Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	19002000	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	30275000	USD
CY2021Q4	us-gaap	Liabilities Current LiabilitiesCurrent	192459000	USD
CY2020Q4	us-gaap	Liabilities Current LiabilitiesCurrent	174453000	USD
CY2021Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	8588000	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	8900000	USD
CY2021Q4	us-gaap	Accrued Income Taxes Noncurrent AccruedIncomeTaxesNoncurrent	6138000	USD
CY2020Q4	us-gaap	Accrued Income Taxes Noncurrent AccruedIncomeTaxesNoncurrent	6888000	USD
CY2021Q4	us-gaap	Postemployment Benefits Liability Noncurrent PostemploymentBenefitsLiabilityNoncurrent	18037000	USD
CY2020Q4	us-gaap	Postemployment Benefits Liability Noncurrent PostemploymentBenefitsLiabilityNoncurrent	21663000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	25887000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	28816000	USD
CY2021Q4	us-gaap	Long Term Loans From Bank LongTermLoansFromBank	103393000	USD
CY2021Q4	cohu	Lease Liability Noncurrent LeaseLiabilityNoncurrent	22040000	USD
CY2020Q4	cohu	Lease Liability Noncurrent LeaseLiabilityNoncurrent	25787000	USD
CY2021Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2020Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2021Q4	us-gaap	Common Stock Value CommonStockValue	48756000	USD
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	42190000	USD
CY2021Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	674777000	USD
CY2020Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	448194000	USD
CY2021Q4	us-gaap	Treasury Stock Value TreasuryStockValue	7324000	USD
CY2020Q4	us-gaap	Treasury Stock Value TreasuryStockValue	-0	USD
CY2021Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	193555000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	26230000	USD
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-27262000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-4326000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	882502000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	512288000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1090346000	USD
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	887214000	USD
CY2020	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	636007000	USD
CY2019	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	583329000	USD
CY2021	us-gaap	Cost Of Goods And Service Excluding Depreciation Depletion And Amortization CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization	500253000	USD
CY2020	us-gaap	Cost Of Goods And Service Excluding Depreciation Depletion And Amortization CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization	364225000	USD
CY2019	us-gaap	Cost Of Goods And Service Excluding Depreciation Depletion And Amortization CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization	353500000	USD
CY2021	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	91963000	USD
CY2020	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	86151000	USD
CY2019	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	86147000	USD
CY2021	us-gaap	Interest Expense InterestExpense	6413000	USD
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	167325000	USD
CY2021	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	126958000	USD
CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	129248000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	142936000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	35414000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	38746000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	39590000	USD
CY2021	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	70815000	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-0	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-0	USD
CY2021	us-gaap	Restructuring Charges RestructuringCharges	1823000	USD
CY2020	us-gaap	Restructuring Charges RestructuringCharges	7623000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	13484000	USD
CY2021	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	100000	USD
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	11249000	USD
CY2019	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2021	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-0	USD
CY2020	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	4495000	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-0	USD
CY2021	us-gaap	Costs And Expenses CostsAndExpenses	685696000	USD
CY2020	us-gaap	Costs And Expenses CostsAndExpenses	632747000	USD
CY2019	us-gaap	Costs And Expenses CostsAndExpenses	635657000	USD
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	201518000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	3260000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	-52328000	USD
CY2020	us-gaap	Interest Expense InterestExpense	13759000	USD
CY2019	us-gaap	Interest Expense InterestExpense	20556000	USD
CY2021	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	239000	USD
CY2020	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	224000	USD
CY2019	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	764000	USD
CY2021	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	411000	USD
CY2020	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-3170000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	43000	USD
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-3411000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	268000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	192344000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-13177000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-72077000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	25019000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	666000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-3082000	USD
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-13843000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-68995000	USD
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	42000	USD
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CY2021	us-gaap	Profit Loss ProfitLoss	167325000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	-13801000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	-69692000	USD
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CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2021Q4	us-gaap	Inventory Net InventoryNet	161053000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	142500000	USD
CY2020	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	4500000	USD
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CY2020	cohu	Net Income Loss Attributable To Noncontrolling Interest Per Diluted Share NetIncomeLossAttributableToNoncontrollingInterestPerDilutedShare	0
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CY2021	us-gaap	Net Income Loss NetIncomeLoss	167325000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-13801000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	-69700000	USD
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CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.00
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.01
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CY2020	cohu	Net Income Loss Attributable To Noncontrolling Interest Per Basic Share NetIncomeLossAttributableToNoncontrollingInterestPerBasicShare	0
CY2019	cohu	Net Income Loss Attributable To Noncontrolling Interest Per Basic Share NetIncomeLossAttributableToNoncontrollingInterestPerBasicShare	0.00
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CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.00
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CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.33
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.69
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47409000
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	41854000
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CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48460000
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	41854000
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	41159000
CY2021	us-gaap	Profit Loss ProfitLoss	167325000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	-13801000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	-69692000	USD
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	8000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	167325000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-13801000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	-69700000	USD
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-22956000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	27321000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-7522000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2602000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2383000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	628000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-67000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	0	USD
CY2021	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessNetOfTax	2515000	USD
CY2020	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessNetOfTax	-0	USD
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	3269000	USD
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	USD
CY2020	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2806000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	14234000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	512288000	USD
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	7324000	USD
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CY2019	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessNetOfTax	-0	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-22936000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	29704000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8150000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	-4000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-22936000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	29704000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-8146000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	144389000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	15903000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-77842000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	0	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	0	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	4000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	144389000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	15903000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-77846000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	545944000	USD
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CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-7526000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	628000	USD
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	9866000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	409000	USD
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2346000	USD
CY2019	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	USD
CY2019	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2771000	USD
CY2019	us-gaap	Minority Interest Period Increase Decrease MinorityInterestPeriodIncreaseDecrease	0	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	14148000	USD
CY2019	us-gaap	Noncontrolling Interest Decrease From Deconsolidation NoncontrollingInterestDecreaseFromDeconsolidation	356000	USD
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CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	27321000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2383000	USD
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	2486000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1102000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-22956000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2602000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-67000	USD
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2510000	USD
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	3564000	USD
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	USD
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	10464000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Reclassification Adjustment From Aoci Realized Upon Sale Or Liquidation Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax	2515000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	14420000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5385000	USD
CY2021	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	1652000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	-285000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	3044000	USD
CY2021	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	223119000	USD
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	882502000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	167325000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-13801000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	-69700000	USD
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	8000	USD
CY2021	us-gaap	Disposal Group Not Discontinued Operation Gain Loss On Disposal DisposalGroupNotDiscontinuedOperationGainLossOnDisposal	70815000	USD
CY2020	us-gaap	Disposal Group Not Discontinued Operation Gain Loss On Disposal DisposalGroupNotDiscontinuedOperationGainLossOnDisposal	35000	USD
CY2019	us-gaap	Disposal Group Not Discontinued Operation Gain Loss On Disposal DisposalGroupNotDiscontinuedOperationGainLossOnDisposal	-1138000	USD
CY2021	cohu	Interest Capitalized Associated With Cloud Computing Implementation InterestCapitalizedAssociatedWithCloudComputingImplementation	91000	USD
CY2020	cohu	Interest Capitalized Associated With Cloud Computing Implementation InterestCapitalizedAssociatedWithCloudComputingImplementation	124000	USD
CY2019	cohu	Interest Capitalized Associated With Cloud Computing Implementation InterestCapitalizedAssociatedWithCloudComputingImplementation	168000	USD
CY2021	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	-0	USD
CY2020	us-gaap	Deconsolidation Gain Or Loss Amount DeconsolidationGainOrLossAmount	-0	USD
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CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-3411000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	268000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-0	USD
CY2021	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	100000	USD
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	11249000	USD
CY2019	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	48568000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	52746000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	58871000	USD
CY2021	cohu	Sharebased Compensation Expense Including Restructuring Charges SharebasedCompensationExpenseIncludingRestructuringCharges	13792000	USD
CY2020	cohu	Sharebased Compensation Expense Including Restructuring Charges SharebasedCompensationExpenseIncludingRestructuringCharges	14234000	USD
CY2019	cohu	Sharebased Compensation Expense Including Restructuring Charges SharebasedCompensationExpenseIncludingRestructuringCharges	14148000	USD
CY2021	cohu	Amortization Of Inventory Stepup And Inventory Related Charges AmortizationOfInventoryStepupAndInventoryRelatedCharges	6523000	USD
CY2020	cohu	Amortization Of Inventory Stepup And Inventory Related Charges AmortizationOfInventoryStepupAndInventoryRelatedCharges	3731000	USD
CY2019	cohu	Amortization Of Inventory Stepup And Inventory Related Charges AmortizationOfInventoryStepupAndInventoryRelatedCharges	8347000	USD
CY2021	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	643000	USD
CY2020	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	1177000	USD
CY2019	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	1110000	USD
CY2021	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	-500000	USD
CY2020	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	1675000	USD
CY2019	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	1017000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	953000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5305000	USD
CY2021	us-gaap	Capitalized Computer Software Amortization1 CapitalizedComputerSoftwareAmortization1	1644000	USD
CY2020	us-gaap	Capitalized Computer Software Amortization1 CapitalizedComputerSoftwareAmortization1	1191000	USD
CY2019	us-gaap	Capitalized Computer Software Amortization1 CapitalizedComputerSoftwareAmortization1	0	USD
CY2021	us-gaap	Gain Loss On Sales Of Assets And Asset Impairment Charges GainLossOnSalesOfAssetsAndAssetImpairmentCharges	-1000	USD
CY2020	us-gaap	Gain Loss On Sales Of Assets And Asset Impairment Charges GainLossOnSalesOfAssetsAndAssetImpairmentCharges	4170000	USD
CY2019	us-gaap	Gain Loss On Sales Of Assets And Asset Impairment Charges GainLossOnSalesOfAssetsAndAssetImpairmentCharges	-173000	USD
CY2021	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	-416000	USD
CY2020	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	91000	USD
CY2019	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	5348000	USD
CY2021	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	-4090000	USD
CY2021	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	135549000	USD
CY2020	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	0	USD
CY2019	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	0	USD
CY2021	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	120886000	USD
CY2020	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	2188000	USD
CY2019	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	11548000	USD
CY2021	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	59123000	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	20210000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-21150000	USD
CY2021	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	35864000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	14982000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-26000	USD
CY2021	cohu	Increase Decrease In Accrued Compensation Warranty And Other Liabilities IncreaseDecreaseInAccruedCompensationWarrantyAndOtherLiabilities	225000	USD
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CY2019	cohu	Increase Decrease In Accrued Compensation Warranty And Other Liabilities IncreaseDecreaseInAccruedCompensationWarrantyAndOtherLiabilities	-9405000	USD
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	17316000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	15058000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-3122000	USD
CY2021	cohu	Increase Decrease In Deferred Profit IncreaseDecreaseInDeferredProfit	4732000	USD
CY2020	cohu	Increase Decrease In Deferred Profit IncreaseDecreaseInDeferredProfit	871000	USD
CY2019	cohu	Increase Decrease In Deferred Profit IncreaseDecreaseInDeferredProfit	997000	USD
CY2021	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-1709000	USD
CY2020	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-1150000	USD
CY2019	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	5996000	USD
CY2021	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	3444000	USD
CY2020	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-2089000	USD
CY2019	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-10719000	USD
CY2021	cohu	Increase Decrease In Operating Lease Right Of Use Assets IncreaseDecreaseInOperatingLeaseRightOfUseAssets	-6746000	USD
CY2020	cohu	Increase Decrease In Operating Lease Right Of Use Assets IncreaseDecreaseInOperatingLeaseRightOfUseAssets	-6831000	USD
CY2019	cohu	Increase Decrease In Operating Lease Right Of Use Assets IncreaseDecreaseInOperatingLeaseRightOfUseAssets	-7159000	USD
CY2021	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	-6852000	USD
CY2020	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	-6437000	USD
CY2019	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	-6083000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	97729000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	49734000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	17269000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	12000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	18660000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	18000000	USD
CY2021	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	157000	USD
CY2020	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	17025000	USD
CY2019	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	1767000	USD
CY2021	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	204699000	USD
CY2020	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	19703000	USD
CY2019	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	315000	USD
CY2020	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	2975000	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	39893000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-18363000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-16548000	USD
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	-0	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	4971000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	9827000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-6572000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-8991000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	149358000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	155930000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	14942000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	6253000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	16324000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	14846000	USD
CY2021	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	624000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1063000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1601000	USD
CY2021	cohu	Inventory Capitalized As Property Plant And Equipment InventoryCapitalizedAsPropertyPlantAndEquipment	1635000	USD
CY2021	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	1376000	USD
CY2020	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	5878000	USD
CY2019	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	5477000	USD
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	206069000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	41056000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	3817000	USD
CY2021	cohu	Proceeds From Repurchase Of Stock Including Awards Settled In Cash Net ProceedsFromRepurchaseOfStockIncludingAwardsSettledInCashNet	-4390000	USD
CY2020	cohu	Proceeds From Repurchase Of Stock Including Awards Settled In Cash Net ProceedsFromRepurchaseOfStockIncludingAwardsSettledInCashNet	2077000	USD
CY2019	cohu	Proceeds From Repurchase Of Stock Including Awards Settled In Cash Net ProceedsFromRepurchaseOfStockIncludingAwardsSettledInCashNet	-16000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	7324000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	-0	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	-0	USD
CY2021	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	223119000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6712000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-38072000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-8183000	USD
CY2021	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-3491000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	129000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-1529000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	140843000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	164921000	USD
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	290201000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	149358000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	155930000	USD
CY2021Q4	us-gaap	Disposal Group Including Discontinued Operation Cash DisposalGroupIncludingDiscontinuedOperationCash	-0	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Cash DisposalGroupIncludingDiscontinuedOperationCash	-0	USD
CY2019Q4	us-gaap	Disposal Group Including Discontinued Operation Cash DisposalGroupIncludingDiscontinuedOperationCash	736000	USD
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	290201000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	149358000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	155194000	USD
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	22717000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	5772000	USD
CY2020	cohu	Inventory Capitalized As Property Plant And Equipment InventoryCapitalizedAsPropertyPlantAndEquipment	1050000	USD
CY2019	cohu	Inventory Capitalized As Property Plant And Equipment InventoryCapitalizedAsPropertyPlantAndEquipment	300000	USD
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	180000
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	113000
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	422000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47409000
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	41854000
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	41159000
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1051000
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48460000
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	41854000
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	41159000
CY2021	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="font-family:'Times New Roman';font-size:10pt;font-variant:normal;margin:0pt;"/> <p style="font-family:Times New Roman;font-size:10pt;font-variant:normal;margin:0pt 0pt 0pt 18pt;"><b>Concentration of Credit Risk</b> – Financial instruments that potentially subject us to significant credit risk consist principally of cash equivalents, short-term investments and trade accounts receivable. We invest in a variety of financial instruments and, by policy, limit the amount of credit exposure with any <em style="font: inherit;">one</em> issuer.</p> <p style="font-family:'Times New Roman';font-size:10pt;font-variant:normal;margin:0pt;"> </p> <p style="font-family:Times New Roman;font-size:10pt;font-variant:normal;margin:0pt 0pt 0pt 18pt;">Our trade accounts receivable are presented net of an allowance for credit losses, which is determined in accordance with the guidance provided by ASC Topic <em style="font: inherit;">326,</em> <i>Financial Instruments-Credit Losses </i>(“ASC <em style="font: inherit;">326”</em>). Our customers include semiconductor manufacturers and semiconductor test subcontractors throughout many areas of the world. While we believe that our allowance for credit losses is adequate and represents our best estimate at <em style="font: inherit;"> December 25, 2021, </em>we will continue to monitor customer liquidity and other economic conditions, including the impact of the COVID-<em style="font: inherit;">19</em> pandemic, which <em style="font: inherit;"> may </em>result in changes to our estimates regarding expected credit losses.</p>
CY2021	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	7100000	USD
CY2020	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	8100000	USD
CY2019	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	4800000	USD
CY2021Q4	us-gaap	Inventory Raw Materials And Supplies Net Of Reserves InventoryRawMaterialsAndSuppliesNetOfReserves	92798000	USD
CY2020Q4	us-gaap	Inventory Raw Materials And Supplies Net Of Reserves InventoryRawMaterialsAndSuppliesNetOfReserves	83755000	USD
CY2021Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	40732000	USD
CY2020Q4	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	44315000	USD
CY2021Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	27523000	USD
CY2020Q4	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	14430000	USD
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	17100000	USD
CY2020Q4	cohu	Deferred Profit DeferredProfit	8700000	USD
CY2020Q4	cohu	Deferred Profit Longterm DeferredProfitLongterm	6700000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	134956000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	131540000	USD
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	70999000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	64624000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	63957000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	66916000	USD
CY2021	us-gaap	Depreciation Depreciation	13200000	USD
CY2020	us-gaap	Depreciation Depreciation	14000000.0	USD
CY2019	us-gaap	Depreciation Depreciation	19300000	USD
CY2021Q4	us-gaap	Capitalized Computer Software Gross CapitalizedComputerSoftwareGross	13500000	USD
CY2021	us-gaap	Capitalized Computer Software Amortization1 CapitalizedComputerSoftwareAmortization1	1600000	USD
CY2020	us-gaap	Capitalized Computer Software Amortization1 CapitalizedComputerSoftwareAmortization1	1200000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	7700000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	8300000	USD
CY2021	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	0	USD
CY2021Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2021Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	21900000	USD
CY2021Q4	cohu	Deferred Profit DeferredProfit	13200000	USD
CY2021Q4	cohu	Deferred Profit Longterm DeferredProfitLongterm	6100000	USD
CY2021Q4	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	0	USD
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	887214000	USD
CY2020	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	636007000	USD
CY2019	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	583329000	USD
CY2021	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	600000	USD
CY2020	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1200000	USD
CY2019	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1100000	USD
CY2021	us-gaap	Foreign Currency Transaction Gain Loss Realized ForeignCurrencyTransactionGainLossRealized	400000	USD
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-27300000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-4300000	USD
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax	-23000000.0	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax	27300000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	238669000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	13635000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	252304000	USD
CY2021	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	21899000	USD
CY2021	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-10614000	USD
CY2021Q4	us-gaap	Goodwill Goodwill	219791000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	89738000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	38700000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	39600000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	34800000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	34800000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	34800000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	26100000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	19300000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	27400000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	311551000	USD
CY2021Q4	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2020Q1	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	35400000	USD
CY2021Q4	us-gaap	Line Of Credit LineOfCredit	3059000	USD
CY2020Q4	us-gaap	Line Of Credit LineOfCredit	5314000	USD
CY2021Q4	cohu	Debt Longterm And Shortterm Combined Amount Gross DebtLongtermAndShorttermCombinedAmountGross	119304000	USD
CY2020Q4	cohu	Debt Longterm And Shortterm Combined Amount Gross DebtLongtermAndShorttermCombinedAmountGross	325508000	USD
CY2021Q4	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	1514000	USD
CY2020Q4	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	5568000	USD
CY2021Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	14397000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	8389000	USD
CY2021Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	103393000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	14795000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	4751000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	4757000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	86892000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	1268000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	6841000	USD
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	119304000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	2000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	36000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	89704000	USD
CY2021	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.08	pure
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	2400000	USD
CY2020	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	2300000	USD
CY2019	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	2000000.0	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	20668000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	2000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	20669000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	57000000.0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	8700000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	83429000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	83408000	USD
CY2021Q4	cohu	Availableforsale Securities Debt Maturities Year Two Through Three Amortized Cost Basis AvailableforsaleSecuritiesDebtMaturitiesYearTwoThroughThreeAmortizedCostBasis	6309000	USD
CY2021Q4	cohu	Available For Sale Securities Debt Maturities Due After One Year Through Three Years Estimated Fair Value AvailableForSaleSecuritiesDebtMaturitiesDueAfterOneYearThroughThreeYearsEstimatedFairValue	6296000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	89738000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	89704000	USD
CY2021	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	0.50	pure
CY2021Q4	us-gaap	Deferred Compensation Liability Current DeferredCompensationLiabilityCurrent	1600000	USD
CY2021Q4	us-gaap	Cash Surrender Value Of Life Insurance CashSurrenderValueOfLifeInsurance	1800000	USD
CY2020Q4	us-gaap	Deferred Compensation Liability Current DeferredCompensationLiabilityCurrent	1800000	USD
CY2020Q4	us-gaap	Cash Surrender Value Of Life Insurance CashSurrenderValueOfLifeInsurance	1800000	USD
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P1Y3M18D
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	9.44
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	12000
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	9.44
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	262000
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.01
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	363000
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.27
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	405000
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.22
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	250000
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	10.03
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	101000
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	10.95
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	42000
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	9.82
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	12000
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	9.44
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	262000
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.01
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	363000
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.27
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	8400000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	1300000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	200000	USD
CY2021Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	400000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	12000
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13792000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14234000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14148000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	722000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	963000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	587000	USD
CY2021	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	13070000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	13271000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	13561000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1000	USD
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	948000	USD
CY2021Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	70000000	USD
CY2021	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	206572
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	7300000	USD
CY2021Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	62700000	USD
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	1103000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	101000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	21000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	130000	USD
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	22862000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5950000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	2173000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	24066000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	5971000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	2303000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	5000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	8000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	98000	USD
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-5313000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-5484000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	953000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5305000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5385000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	25019000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	666000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-3082000	USD
CY2020Q4	cohu	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	5146000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	37393000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	5695000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	5306000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	2222000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	2210000	USD
CY2021Q4	cohu	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	4500000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	30588000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-25005000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-72669000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	161756000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	11828000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	592000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	192344000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-13177000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-72077000	USD
CY2021Q4	cohu	Deferred Tax Assets Inventory And Warranty Reserves DeferredTaxAssetsInventoryAndWarrantyReserves	12166000	USD
CY2020Q4	cohu	Deferred Tax Assets Inventory And Warranty Reserves DeferredTaxAssetsInventoryAndWarrantyReserves	11720000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	44806000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	56777000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	31264000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	2674000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	4309000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	103327000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	122861000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	76250000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	86124000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	27077000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	36737000	USD
CY2021Q4	cohu	Deferred Tax Liabilities Asset Basis Differences DeferredTaxLiabilitiesAssetBasisDifferences	39929000	USD
CY2020Q4	cohu	Deferred Tax Liabilities Asset Basis Differences DeferredTaxLiabilitiesAssetBasisDifferences	52012000	USD
CY2021Q4	cohu	Deferred Tax Liabilities Operating Lease Rightofuse Assets DeferredTaxLiabilitiesOperatingLeaseRightofuseAssets	4066000	USD
CY2020Q4	cohu	Deferred Tax Liabilities Operating Lease Rightofuse Assets DeferredTaxLiabilitiesOperatingLeaseRightofuseAssets	4706000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	4207000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	3119000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	48202000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	59837000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	21125000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	23100000	USD
CY2021Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	4762000	USD
CY2020Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	5716000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	25887000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	28816000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	21125000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	23100000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	76300000	USD
CY2021	cohu	Effective Income Tax Rate Reconciliation Deemed Dividends Amount EffectiveIncomeTaxRateReconciliationDeemedDividendsAmount	693000	USD
CY2020	cohu	Effective Income Tax Rate Reconciliation Deemed Dividends Amount EffectiveIncomeTaxRateReconciliationDeemedDividendsAmount	1224000	USD
CY2019	cohu	Effective Income Tax Rate Reconciliation Deemed Dividends Amount EffectiveIncomeTaxRateReconciliationDeemedDividendsAmount	1453000	USD
CY2021	cohu	Effective Income Tax Rate Reconciliation Gilti Amount EffectiveIncomeTaxRateReconciliationGILTIAmount	9343000	USD
CY2020	cohu	Effective Income Tax Rate Reconciliation Gilti Amount EffectiveIncomeTaxRateReconciliationGILTIAmount	4191000	USD
CY2019	cohu	Effective Income Tax Rate Reconciliation Gilti Amount EffectiveIncomeTaxRateReconciliationGILTIAmount	2480000	USD
CY2021	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-1023000	USD
CY2020	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-1512000	USD
CY2019	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-1266000	USD
CY2021	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	552000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	86100000	USD
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	40392000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-2757000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-15136000	USD
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	2246000	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-1160000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-1097000	USD
CY2021	cohu	Income Tax Reconciliation Settlements Adjustments And Releases From Statute Expirations IncomeTaxReconciliationSettlementsAdjustmentsAndReleasesFromStatuteExpirations	-787000	USD
CY2020	cohu	Income Tax Reconciliation Settlements Adjustments And Releases From Statute Expirations IncomeTaxReconciliationSettlementsAdjustmentsAndReleasesFromStatuteExpirations	-118000	USD
CY2019	cohu	Income Tax Reconciliation Settlements Adjustments And Releases From Statute Expirations IncomeTaxReconciliationSettlementsAdjustmentsAndReleasesFromStatuteExpirations	-1204000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Credits Research IncomeTaxReconciliationTaxCreditsResearch	943000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Credits Research IncomeTaxReconciliationTaxCreditsResearch	46000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Credits Research IncomeTaxReconciliationTaxCreditsResearch	1458000	USD
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-4802000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	727000	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	587000	USD
CY2021	cohu	Effective Income Tax Rate Reconciliation Excess Executive Compensation EffectiveIncomeTaxRateReconciliationExcessExecutiveCompensation	1608000	USD
CY2020	cohu	Effective Income Tax Rate Reconciliation Excess Executive Compensation EffectiveIncomeTaxRateReconciliationExcessExecutiveCompensation	491000	USD
CY2019	cohu	Effective Income Tax Rate Reconciliation Excess Executive Compensation EffectiveIncomeTaxRateReconciliationExcessExecutiveCompensation	190000	USD
CY2021	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-9882000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-1691000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	11270000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	12378000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	-0	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	-0	USD
CY2020	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	1317000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	1099000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	25019000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	666000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-3082000	USD
CY2021	cohu	Increase Decrease Of Net Income Due To Impact Of Tax Holidays IncreaseDecreaseOfNetIncomeDueToImpactOfTaxHolidays	4500000	USD
CY2021	cohu	Increase Decrease Of Earning Per Share Due To Impact Of Tax Holidays IncreaseDecreaseOfEarningPerShareDueToImpactOfTaxHolidays	0.09
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	33391000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	33696000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	34740000	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	5300000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	5900000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	7000000.0	USD
CY2020	cohu	Increase Decrease Of Net Income Due To Impact Of Tax Holidays IncreaseDecreaseOfNetIncomeDueToImpactOfTaxHolidays	3600000	USD
CY2020	cohu	Increase Decrease Of Earning Per Share Due To Impact Of Tax Holidays IncreaseDecreaseOfEarningPerShareDueToImpactOfTaxHolidays	0.09
CY2019	cohu	Increase Decrease Of Net Income Due To Impact Of Tax Holidays IncreaseDecreaseOfNetIncomeDueToImpactOfTaxHolidays	2100000	USD
CY2019	cohu	Increase Decrease Of Earning Per Share Due To Impact Of Tax Holidays IncreaseDecreaseOfEarningPerShareDueToImpactOfTaxHolidays	0.05
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	33696000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	34740000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	34873000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	686000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	817000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1231000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	83000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	425000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	484000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	1012000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	304000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	957000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	-0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	1134000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	30000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Foreign Currency Translation UnrecognizedTaxBenefitsIncreasesResultingFromForeignCurrencyTranslation	104000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Foreign Currency Translation UnrecognizedTaxBenefitsIncreasesResultingFromForeignCurrencyTranslation	2000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Foreign Currency Translation UnrecognizedTaxBenefitsIncreasesResultingFromForeignCurrencyTranslation	107000	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	800000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1000000.0	USD
CY2021	cohu	Unrecognized Tax Benefits Interest Expense Net Of Accrued Interest Reversed UnrecognizedTaxBenefitsInterestExpenseNetOfAccruedInterestReversed	-200000	USD
CY2020	cohu	Unrecognized Tax Benefits Interest Expense Net Of Accrued Interest Reversed UnrecognizedTaxBenefitsInterestExpenseNetOfAccruedInterestReversed	-300000	USD
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	887214000	USD
CY2020	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	636007000	USD
CY2019	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	583329000	USD
CY2021	cohu	Profit Loss From Operating Segment ProfitLossFromOperatingSegment	141933000	USD
CY2020	cohu	Profit Loss From Operating Segment ProfitLossFromOperatingSegment	4474000	USD
CY2019	cohu	Profit Loss From Operating Segment ProfitLossFromOperatingSegment	-42437000	USD
CY2021	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	70815000	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2021	us-gaap	Interest Expense InterestExpense	6413000	USD
CY2020	us-gaap	Interest Expense InterestExpense	13759000	USD
CY2019	us-gaap	Interest Expense InterestExpense	20556000	USD
CY2021	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	239000	USD
CY2020	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	224000	USD
CY2019	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	764000	USD
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-3411000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	268000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	192344000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-13177000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-72077000	USD
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	48568000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	52746000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	58871000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	12000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	18660000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	18000000	USD
CY2021Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	0	USD
CY2020Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	0	USD
CY2019Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	3618000	USD
CY2021Q4	us-gaap	Assets Assets	1259044000	USD
CY2020Q4	us-gaap	Assets Assets	1090346000	USD
CY2019Q4	us-gaap	Assets Assets	1077710000	USD
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	887214000	USD
CY2020	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	636007000	USD
CY2019	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	583329000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	63957000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	66916000	USD
CY2021Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	397111000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	485989000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P25Y
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	7638000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	8374000	USD
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	2192000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	2110000	USD
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	69000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	93000	USD
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	86000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	84000	USD
CY2021	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	2000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	57000	USD
CY2021	us-gaap	Sublease Income SubleaseIncome	81000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	25060000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	29203000	USD
CY2021Q4	cohu	Lease Rightofuse Asset LeaseRightofuseAsset	25483000	USD
CY2020Q4	cohu	Lease Rightofuse Asset LeaseRightofuseAsset	29689000	USD
CY2021Q4	cohu	Lease Liability LeaseLiability	27093000	USD
CY2020Q4	cohu	Lease Liability LeaseLiability	31253000	USD
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y10M24D
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y3M18D
CY2021Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P1Y9M18D
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P2Y3M18D
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.063	pure
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.063	pure
CY2021Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.007	pure
CY2020Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.000	pure
CY2021Q4	us-gaap	Finance Lease Right Of Use Asset Accumulated Amortization FinanceLeaseRightOfUseAssetAccumulatedAmortization	100000	USD
CY2020	us-gaap	Sublease Income SubleaseIncome	113000	USD
CY2021	us-gaap	Lease Cost LeaseCost	9906000	USD
CY2020	us-gaap	Lease Cost LeaseCost	10605000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	5050000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	11000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due Year Three LesseeLeaseLiabilityPaymentsDueYearThree	5061000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	4912000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	11000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due Year Four LesseeLeaseLiabilityPaymentsDueYearFour	4923000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2617000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	2000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due Year Five LesseeLeaseLiabilityPaymentsDueYearFive	2619000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	9656000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	0	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due After Year Five LesseeLeaseLiabilityPaymentsDueAfterYearFive	9656000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	34021000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	234000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due LesseeLeaseLiabilityPaymentsDue	34255000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	7158000	USD
CY2021Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	4000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	6341000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	170000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due Next Twelve Months LesseeLeaseLiabilityPaymentsDueNextTwelveMonths	6511000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	5445000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	40000	USD
CY2021Q4	cohu	Lessee Lease Liability Payments Due Year Two LesseeLeaseLiabilityPaymentsDueYearTwo	5485000	USD
CY2021Q4	cohu	Lessee Lease Liability Undiscounted Excess Amount LesseeLeaseLiabilityUndiscountedExcessAmount	7162000	USD
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	230000	USD
CY2021Q4	cohu	Lease Liability LeaseLiability	27093000	USD
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	7628000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	8079000	USD
CY2021	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	1000	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	57000	USD
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	186000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	146000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	54000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	489000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	3866000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	2403000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	6136000	USD
CY2020	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	11000	USD
CY2020Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	6382000	USD
CY2019Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	6155000	USD
CY2018Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	8014000	USD
CY2021	us-gaap	Product Warranty Accrual Warranties Issued ProductWarrantyAccrualWarrantiesIssued	13389000	USD
CY2020	us-gaap	Product Warranty Accrual Warranties Issued ProductWarrantyAccrualWarrantiesIssued	6173000	USD
CY2019	us-gaap	Product Warranty Accrual Warranties Issued ProductWarrantyAccrualWarrantiesIssued	6714000	USD
CY2021	us-gaap	Product Warranty Accrual Payments ProductWarrantyAccrualPayments	11135000	USD
CY2020	us-gaap	Product Warranty Accrual Payments ProductWarrantyAccrualPayments	5946000	USD
CY2019	us-gaap	Product Warranty Accrual Payments ProductWarrantyAccrualPayments	8573000	USD
CY2021	cohu	Product Warranty Accrual Warrant Liability Transferred ProductWarrantyAccrualWarrantLiabilityTransferred	-945000	USD
CY2020	cohu	Product Warranty Accrual Warrant Liability Transferred ProductWarrantyAccrualWarrantLiabilityTransferred	0	USD
CY2019	cohu	Product Warranty Accrual Warrant Liability Transferred ProductWarrantyAccrualWarrantLiabilityTransferred	0	USD
CY2021Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	7691000	USD
CY2020Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	6382000	USD
CY2019Q4	us-gaap	Product Warranty Accrual ProductWarrantyAccrual	6155000	USD
CY2021Q3	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	pure
CY2020	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	432000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	478000	USD
CY2020	cohu	Disposal Group Including Discontinued Operation Impairment DisposalGroupIncludingDiscontinuedOperationImpairment	-0	USD
CY2019	cohu	Disposal Group Including Discontinued Operation Impairment DisposalGroupIncludingDiscontinuedOperationImpairment	1086000	USD
CY2020	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	35000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	0	USD
CY2020	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	46000	USD
CY2019	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	-608000	USD
CY2020	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	4000	USD
CY2019	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	89000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	42000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-697000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	-7522000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	0	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-7522000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPortionAttributableToParent	856000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent	-228000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	628000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-8378000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	228000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8150000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	27321000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	0	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	27321000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPortionAttributableToParent	-2599000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent	216000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2383000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	29920000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-216000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	29704000	USD
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	-22859000	USD
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	-97000	USD
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-22956000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPortionAttributableToParent	-2920000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent	318000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-2602000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-67000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-67000	USD
CY2021	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessBeforeTax	2515000	USD
CY2021	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessTax	0	USD
CY2021	cohu	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Business Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAociForSaleOfBusinessNetOfTax	2515000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-22521000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-415000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-22936000	USD

Files In Submission

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$COHU
COHU INC Stock $cohu

2021 Q4 Form 10-K Financial Statement

#000143774922003768 Filed on February 18, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COHU COHU INC Stock $cohu

2021 Q4 Form 10-K Financial Statement

#000143774922003768 Filed on February 18, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COHU
COHU INC Stock $cohu