Document And Entity Information ecd_TrdArrIndTitle Trading Arrangement, Individual Title Statistical Measurement [Axis] ecd_TrdArrIndName Trading Arrangement, Individual Name Note To Financial Statement Details Textual ecd_TrdArrExpirationDate Trading Arrangement Expiration Date Significant Accounting Policies Income tax expense (benefit) Income Tax Expense (Benefit) ecd_TrdArrAdoptionDate Trading Arrangement Adoption Date Note 2 - Net Income Per Share ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Note 3 - Revenue From Contracts With Customers ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Note 4 - Balance Sheet Components Trading Arrangements, by Individual [Table] Note 6 - Restructuring Material Terms of Trading Arrangement [Text Block] Note 7 - Leases Note 8 - Intangible Assets Note 9 - Stock-based Compensation Note 13 - Segment Reporting Note 2 - Net Income Per Share - Earnings Per Share (Details) Minimum [Member] Note 3 - Revenue from Contracts with Customers - Disaggregation of Revenue (Details) lscc_PolicyTable Note 3 - Revenue From Contracts With Customers - Contract Balance (Details) Statistical Measurement [Domain] Note 4 - Balance Sheet Components - Accounts Receivable (Details) Maximum [Member] ecd_TrdArrSecuritiesAggAvailAmt Trading Arrangement, Securities Aggregate Available Amount Note 4 - Balance Sheet Components - Inventories (Details) Share Repurchase Program [Axis] Note 4 - Balance Sheet Components - Property, Plant and Equipment (Details) Share Repurchase Program [Domain] Note 4 - Balance Sheet Components - Accrued Liabilities (Details) Note 4 - Balance Sheet Components - Accrued Liabilities (Details) (Parentheticals) Note 4 - Balance Sheet Components - Other Long-Term Liabilities (Details) us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable, net Note 6 - Restructuring - Activity Related to Restructuring Plans (Details) Note 7 - Leases - Lease Balance Classifications Within the Consolidated Balance Sheets and Lease Activity (Details) Note 7 - Leases - Maturities of Operating Lease Liabilities (Details) Note 8 - Intangible Assets - Amortization Expense (Details) Note 9 - Stock-based Compensation - Stock-based Compensation (Details) Note 9 - Stock-based Compensation - Share Based Compensation Performance Shares Award Market Condition or Performance Condition (Details) us-gaap_CostDirectLabor Cost of revenue Note 13 - Segment Reporting - Segment Reporting (Details) Notes To Financial Statements Notes To Financial Statements [Abstract] Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent lscc_PaymentsForRestructuringOrOtherwiseSettled Costs paid or otherwise settled The amount of payments for the restructuring costs or the costs that were otherwise settled. us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities Accrued payroll obligations us-gaap_LaborAndRelatedExpense Selling, general, and administrative Income Tax Jurisdiction [Domain] The 2022 Credit Agreement [Member[ Represents information pertaining to the 2022 Credit Agreement. Performance Shares [Member] us-gaap_IncreaseDecreaseInInventories Inventories, net Segment Reporting [Text Block] Employee Severance [Member] Type of Restructuring [Domain] Award Type [Axis] Segment Reporting [Table Text Block] Adjustments to reconcile net income to net cash provided by (used in) operating activities: Preferred stock, $.01 par value, 10,000,000 shares authorized, none issued and outstanding Restructuring Cost [Table] us-gaap_Liabilities Total liabilities Technology, Customer Relationships, Trade Names, and Trademarks [Member] Represents Technology, Customer Relationships, Trade Names, and Trademarks. us-gaap_AllocatedShareBasedCompensationExpense Share-Based Payment Arrangement, Expense us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders' equity Title and Position [Axis] Segment Reporting [Table] us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other assets us-gaap_ShareBasedCompensation Stock-based compensation expense Selling, general, and administrative Subsequent Event [Member] Lessee, Lease, Description [Table] Share-Based Payment Arrangement [Text Block] Americas [Member] Changes in assets and liabilities: us-gaap_IncreaseDecreaseInAccountsPayable Accounts payable Preferred stock, shares issued (in shares) us-gaap_FiniteLivedIntangibleAssetUsefulLife Intangible Asset, Finite-Lived, Useful Life (Year) Europe [Member] Preferred stock, shares outstanding (in shares) Asia [Member] Preferred stock, shares authorized (in shares) Licensing Agreements [Member] Preferred stock, par value per share (in dollars per share) us-gaap_IncreaseDecreaseInAccruedLiabilities Accrued liabilities Net change in unrealized gains (losses) on cash flow hedges us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net increase (decrease) in cash and cash equivalents Effect of exchange rate change on cash New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_RestructuringAndRelatedCostCostIncurredToDate1 Restructuring and Related Cost, Cost Incurred to Date us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Beginning cash and cash equivalents Ending cash and cash equivalents Concentration Risk, Credit Risk, Policy [Policy Text Block] Share-Based Payment Arrangement, Tranche One [Member] Statement [Table] Credit Facility [Axis] Operating lease payments Operating cash used for payments on lease liabilities Credit Facility [Domain] us-gaap_LineOfCreditFacilityCommitmentFeeAmount Line of Credit Facility, Commitment Fee Amount Share-Based Payment Arrangement, Tranche Two [Member] Share-Based Payment Arrangement, Tranche Three [Member] Sales Channel, Directly to Consumer [Member] us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] Information pertaining to TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile. Operating lease right-of-use assets obtained in exchange for lease obligations us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity Line of Credit Facility, Remaining Borrowing Capacity srt_StockRepurchaseProgramAuthorizedAmount1 Share Repurchase Program, Authorized, Amount us-gaap_StockIssuedDuringPeriodValueIssuedForServices Stock Issued During Period, Value, Issued for Services Product and Service [Domain] Product and Service [Axis] us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total lease payments us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsAndNonoptionEquityInstrumentsVestedInPeriodNumberOfShares Vested, Shares (in shares) Number of vested options and non-option equity instruments. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths 2027 Repurchase Program 2025 [Member] Represents information pertaining to Repurchase Program 2025. Accretion of lease liabilities us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear 2026 (Remaining 2 quarters) Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree 2029 Depreciation and amortization The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets, excluding amortization of right of use assets and finance costs. . us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo 2028 Statement [Line Items] us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour 2030 Common stock, shares issued (in shares) Grantee Status [Domain] Common stock, shares outstanding (in shares) Balances (in shares) Balances (in shares) Award Type [Domain] Share-Based Payment Arrangement, Employee [Member] Common stock, shares authorized (in shares) Grantee Status [Axis] us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1 Share Repurchase Program, Remaining Authorized, Amount Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Common stock, $.01 par value, 300,000,000 shares authorized; 137,187,000 shares issued and outstanding as of July 4, 2026 and 136,771,000 shares issued and outstanding as of January 3, 2026 Supplier [Axis] Schedule of Inventory, Current [Table Text Block] Supplier [Domain] Proceeds from issuance of common stock us-gaap_AccountsPayableCurrent Accounts payable us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables us-gaap_ProceedsFromLinesOfCredit Proceeds from Lines of Credit Total comprehensive income us-gaap_ComprehensiveIncomeNetOfTax Comprehensive income Contingencies Disclosure [Text Block] Subsequent Events [Text Block] Concentration Risk Type [Axis] Accrued liabilities Accrued Liabilities, Current Total accrued liabilities us-gaap_EmployeeRelatedLiabilitiesCurrent Accrued payroll obligations Amortization of right-of-use assets Amortization of right-of-use assets during the period us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less: amount representing interest Long-term operating lease liabilities, net of current portion Present value of lease liabilities us-gaap_OperatingLeaseLiability Balance Balance Other accrued liabilities Current portion of operating lease liabilities Less: Current portion of operating lease liabilities (included in Accrued liabilities) Accounts Receivable [Member] Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Concentration Risk Type [Domain] Income Tax Jurisdiction, Domestic Federal [Member] CHINA Offsetting Assets [Table] Intangible Asset, Finite-Lived, Class [Axis] Statement of Stockholders' Equity [Abstract] Statement of Comprehensive Income [Abstract] Intangible Asset, Finite-Lived, Class [Domain] Statement of Cash Flows [Abstract] us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent Change in actuarial valuation of defined benefit pension us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent Translation adjustment Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other comprehensive income (loss) Stockholders' equity: Equity Components [Axis] Operating lease liabilities, current and long-term portions Equity Component [Domain] AOCI Attributable to Parent [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Cost of revenue lscc_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour Thereafter Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). AMI TopCo Inc. [Member] Represents AMI TopCo Inc. Total property and equipment, net Property and equipment, less accumulated depreciation of $122,487 at July 4, 2026 and $123,654 at January 3, 2026 Accrued purchases of plant and equipment INDIA Prior year incentive compensation settled in equity Amount of increase (decrease) in additional paid in capital (APIC) from prior year incentive compensation settled in equity. Subsequent Event Type [Domain] JAPAN Subsequent Event [Table] Subsequent Event Type [Axis] Deferred income taxes Intangible Assets [Member] Represents intangible assets. Stock-based compensation expense Large Distributor Two [Member] Information pertaining to the second large distributor. Large Distributor One [Member] Information pertaining to the first large distributor. Other Asia [Member] Information pertaining to other Asia. lscc_PercentageOfRevenue Percentage of revenue Represents the percentage of revenue. Sales Channel, Through Intermediary [Member] us-gaap_AccountsReceivableNet Accounts receivable, net Liabilities, Current [Abstract] lscc_NumberOfDistributors Number of Distributors Represents the number of distributors. MALAYSIA us-gaap_LiabilitiesCurrent Total current liabilities Secured Overnight Financing Rate (SOFR) [Member] Treasury Stock [Text Block] Accounts receivable, net PHILIPPINES Q3 2024 Plan 1 [Member] Represents Q3 2024 Plan. Long-term portion of liability for non-cancellable contracts Amount of liability for non-cancelable contracts, classified as noncurrent. us-gaap_PaymentsToAcquireIntangibleAssets Cash paid for software and intellectual property licenses Revenue Benchmark [Member] Other Commitments [Table] Long-Term Debt [Text Block] Accumulated depreciation Accumulated other comprehensive loss us-gaap_PaymentsToAcquireInvestments Cash paid for long-term investment us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization Intangible Asset, Finite-Lived, Accumulated Amortization Fiscal Period, Policy [Policy Text Block] us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Income before income taxes lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsAndNonOptionEquityInstrumentsNonvestedNumberOfShares Balance, Shares (in shares) Balance, Shares (in shares) Number of non-vested options and non-option equity instruments outstanding. Additional paid-in capital lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsAndNonOptionEquityInstrumentsNonvestedGrantsInPeriodGross Granted, Shares (in shares) Gross number of nonvested share options and non-option equity instruments (or share units) granted during the period. lscc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndNonOptionEquityInstrumentsNonvestedEffectOfVestingMultiplier Effect of vesting multiplier, Shares (in shares) The number of shares awarded and vested due to the effect of the vesting multiplier during the period on stock (or unit) option and non-option instrument plans. Canceled, Shares (in shares) Number of non-vested options and non-option equity instruments forfeited. TAIWAN Prepaid expenses and other current assets us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Capital expenditures Lessee, Operating Leases [Text Block] Employee equity incentive award stock issuance, net of tax withholding UNITED STATES us-gaap_DebtInstrumentCarryingAmount Long-Term Debt, Gross us-gaap_StockRepurchasedAndRetiredDuringPeriodValue Stock Repurchased and Retired During Period, Value Repurchase of common stock Basis of Accounting and Use Of Estimates, Policy [Policy Text Block] Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS). and for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles. Current assets: us-gaap_AssetsCurrent Total current assets Employee equity incentive award stock issuance, net of tax withholding (in shares) Gross margin Gross margin Restricted Stock Units (RSUs) [Member] Accounts receivable Debt Instrument, Name [Domain] us-gaap_StockRepurchasedAndRetiredDuringPeriodShares Stock Repurchased and Retired During Period, Shares (in shares) Repurchase of common stock (in shares) Schedule of Long-Term Debt Instruments [Table] Debt Instrument [Axis] Cash flows from operating activities: Cash flows from investing activities: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by (used in) operating activities Work in progress Cash flows from financing activities: us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash provided by (used in) investing activities us-gaap_PaymentsOfDebtIssuanceCosts Cash paid for debt issuance costs us-gaap_TreasuryStockAcquiredAverageCostPerShare Shares Acquired, Average Cost Per Share (in dollars per share) Finished goods us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by (used in) financing activities Restructuring Type [Axis] lscc_LesseeOperatingLeaseOptionToExtendPeriod Lessee, Operating Lease, Option to Extend, Period (Year) Represents option to extend period for operating lease. lscc_LesseeOperatingLeaseOptionToTerminatePeriod Lessee, Operating Lease, Option to Terminate Period (Year) Represents option to terminate period for operating lease of lessee. Accounting Policies [Abstract] Segments [Domain] us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent Less: Allowance for credit losses Segments [Axis] Income Statement [Abstract] us-gaap_NumberOfOperatingSegments Number of Operating Segments us-gaap_NumberOfReportableSegments Number of Reportable Segments Distributors [Member] Represents the distributors of the company. Change in deferred income tax provision Other long-term liabilities us-gaap_OtherSundryLiabilitiesNoncurrent Net income Net income Net income us-gaap_AmortizationOfIntangibleAssets Amortization of intangible assets Senior Vice President and Chief Strategy and Marketing Officer [Member] Senior Vice President and Chief Strategy and Marketing Officer Interest income (expense), net us-gaap_OtherNoncashIncomeExpense Other non-cash adjustments us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Income Tax Disclosure [Text Block] Restricted Stock [Member] Share-Based Payment Arrangement [Member] Accounting Standards Update and Change in Accounting Principle [Table] lscc_RightofuseAssetsObtainedForNewAndModifiedLeaseContractsDuringThePeriod Right-of-use assets obtained for new or renewed lease contracts during the period represents right-of-use assets obtained for new and modified lease contracts during the period. Supplemental Balance Sheet Disclosures [Text Block] Vesting [Axis] Statement of Financial Position [Abstract] Vesting [Domain] Class of Treasury Stock [Table] Income taxes paid, net of refunds Other long-term assets us-gaap_PaymentsForRepurchaseOfCommonStock Repurchase of common stock Document Type Operating expenses: Document Information [Line Items] Document Quarterly Report us-gaap_ConcentrationRiskPercentage1 Concentration Risk, Percentage us-gaap_LesseeOperatingLeaseTermOfContract Lessee, Operating Lease, Term of Contract (Year) us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1 Operating Lease, Weighted Average Remaining Lease Term (Year) Document Information [Table] us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) The 2026 Credit Agreement [Member] Represents information pertaining to the 2026 credit agreement. Senior Secured Bridge Facility [Member] Represents information pertaining to the senior secured bridge facility. lscc_LineOfCreditFacilityPercentageOfPrincipalPayableYearTwoThroughFour Line of Credit Facility, Percentage of Principal Payable, Year Two Through Four The percentage of the principal that is payable during certain periods under a line of credit facility in the second year through the fourth. Dilutive effect of employee equity incentive awards (in shares) Entity Interactive Data Current lscc_LineOfCreditFacilityPercentageOfPrincipalPaymentsAfterYearFour Line of Credit Facility, Percentage of Principal Payments, After Year Four The percentage of the principal that is payable during certain periods under a line of credit facility in the years after the fourth. us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares (in shares) Document Transition Report Intangible Asset, Finite-Lived, Amortization Expense [Table Text Block] Diluted (in shares) us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding Shares used in diluted Net income per share (in shares) Total operating expenses Total operating expenses lscc_LineOfCreditFacilityPercentageOfPrincipalPayableYearOne Line of Credit Facility, Percentage of Principal Payable, Year One The percentage of the principal that is payable during certain periods under a line of credit facility in the first year. Net income per share: Senior Secured Delayed Draw Term Loan Facility [Member] Represents information pertaining to the senior secured delayed draw term loan facility. Senior Secured Revolving Loan Facility [Member] Represents information pertaining to the senior secured revolving loan facility. Basic (in shares) Shares used in basic Net income per share (in shares) Derivative Instrument [Axis] us-gaap_DebtInstrumentTerm Debt Instrument, Term (Year) Antidilutive Security, Excluded EPS Calculation [Table] lscc_AllocatedSharebasedCompensationExpenseUpdatesToExpectedAchievementOfPerformanceConditions Allocated Share-based Compensation Expense, Updates to Expected Achievement of Performance Conditions Amount of allocated share-based compensation expense stemming from updates to expected achievement of performance conditions. Basic (in dollars per share) us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost Research and development Effective Income Tax Rate Reconciliation [Table] Single Reportable Segment [Member] Represents information pertaining to a single reportable segment. Title and Position [Domain] lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageBasedOnMarketConditions Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions Percentage of vesting of award under share-based payment arrangement based on market conditions. Income Tax Jurisdiction [Axis] Intangible assets, net us-gaap_IntangibleAssetsNetExcludingGoodwill lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageOfMarketConditionAchieved Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved The percentage of market condition achieved for awards to vest under share based payment arrangement. Write-off unamortized debt costs Restructuring and other Amount of expenses associated with exit or disposal activities pursuant to an authorized plan and other miscellaneous costs. us-gaap_FiniteLivedIntangibleAssetsNet Intangible Asset, Finite-Lived, after Accumulated Amortization Document Fiscal Period Focus Document Fiscal Year Focus Amendment Flag Restructuring and Related Activities Disclosure [Text Block] Common Stock [Member] Sell-through Distributors Concentration Risk [Member] Represents sell-through distribution concentration risk. us-gaap_RestructuringReserve Accrued Restructuring Accrued Restructuring Goodwill Restructuring lscc_OperatingLeaseLiabilitiesAdjustmentsForPresentValueForeignCurrencyAndRestructuringLiabilityEffects Adjustments for present value and foreign currency effects Amount of adjustments for present value, foreign currency, and restructuring liability effects on operating lease liabilities. Document Period End Date Lessee, Operating Lease Right-of-Use Assets and Liabilities [Table Text Block] The tabular disclosure of lease right of use assets and liabilities for operating leases of the lessee. Lease liabilities accrued for new or renewed lease contracts during the period Amount of increase in operating lease liability from additional liabilities incurred during the period. Legal Entity [Axis] us-gaap_OperatingLeaseCost Operating Lease, Cost Adjustments for present value and foreign currency effects Amount of adjustments for present value and foreign currency effects on right-of-use assets under operating lease. Business Combination [Domain] Entity File Number Lease Termination and Fixed Assets [Member] Represents lease termination and fixed assets. Entity Tax Identification Number Business Combination [Axis] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table] Supplemental disclosure of cash flow information and non-cash investing and financing activities: Entity [Domain] Entity Central Index Key us-gaap_RestructuringAndRelatedCostIncurredCost Restructuring and Related Cost, Incurred Cost Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code Current Fiscal Year End Date Other [Member] Represents other. Fair Value Measurement, Policy [Policy Text Block] Current portion of liability for non-cancellable contracts Amount of liability for non-cancelable contracts, classified as current. Contract with Customer, Sales Channel [Domain] Research and development Entity Filer Category lscc_ContractWithCustomerLiabilityReleaseOfAccrualsForRecognizedStockRotationAndScrapReturns Less: Release of accruals for recognized stock rotation and scrap returns Represents release of accruals for recognized stock rotation and scrap returns for contract with customer liabilities. Entity Shell Company Accruals for estimated future stock rotation and scrap returns Represents accrued for estimated future stock rotation and scrap returns for contract with customer liability. Contract with Customer, Sales Channel [Axis] Entity Emerging Growth Company us-gaap_DerivativeNotionalAmount Derivative, Notional Amount Entity Small Business Revenues recorded during the period us-gaap_ContractWithCustomerAssetReclassifiedToReceivable Transferred to Accounts receivable or collected Amortization of acquired intangible assets Amortization of acquired intangible assets Represents amortization of intangible assets acquired. us-gaap_OperatingIncomeLoss Income from operations Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] us-gaap_ContractWithCustomerAssetNet Contract assets, balance Contract assets, balance lscc_LineOfCreditFacilityCommitmentFeeAmortized Line Of Credit Facility , Commitment Fee, Amortized Amount of commitment fee amortized in a line of credit facility. lscc_LineOfCreditFacilityCommitmentFeeUnamortized Line of Credit Facility, Commitment Fee, Unamortized Amount of unamortized commitment fees for a line of credit facility. Entity Address, State or Province Entity Address, City or Town Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Retained earnings Entity Address, Address Line One City Area Code us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Restricted stock unit tax withholdings Local Phone Number Revenue from Contract with Customer [Text Block] Entity Address, Postal Zip Code Title of 12(b) Security Security Exchange Name Trading Symbol Derivatives, Policy [Policy Text Block] Class of Stock [Axis] Base Rate [Member] Variable Rate [Axis] Variable Rate [Domain] Entity Common Stock, Shares Outstanding Other comprehensive income (loss), net of tax: Cash Flow Hedging [Member] Earnings Per Share [Text Block] Executive Officer [Member] Acquisition related Shares used in per share calculations: Property, Plant, and Equipment [Table] Common stock, par value per share (in dollars per share) Hedging Relationship [Axis] Derivative Contract [Domain] Other income (expense), net us-gaap_Assets Total assets Cash and cash equivalents Other Restructuring [Member] Geographical [Domain] Geographical [Axis] Diluted (in dollars per share) us-gaap_ContractWithCustomerLiability Contract liabilities, balance Contract liabilities, balance us-gaap_PaymentsForRestructuring Costs paid or otherwise settled us-gaap_PaymentsToAcquireBusinessesGross Payments to Acquire Businesses, Gross Contract liabilities Share-Based Payment Arrangement, Performance Shares, Outstanding Activity [Table Text Block] Other Liabilities [Table Text Block] Intangible Asset [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Restructuring Plan [Domain] Restructuring Plan [Axis] Individual [Axis] Intangible Asset, Finite-Lived [Table] Product [Member] Inventories, net Total inventories, net All Individuals [Member] Foreign Countries [Member] Information pertaining to foreign countries. Hedging Relationship [Domain] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] us-gaap_StockholdersEquity Total stockholders' equity Balances Balances Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Foreign Exchange Forward [Member] Operating lease right-of-use assets Balance Balance Other long-term liabilities Total other long-term liabilities ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] Property, Plant, and Equipment [Table Text Block] Revenue Revenue ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Contingencies (Note 12)