XML 80 R62.htm IDEA: XBRL DOCUMENT
v3.20.4

Note 10 - Stock-Based Compensation Plans (Details Textual) $ / shares in Units, $ in Thousands |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
May 31, 2012 shares | May 31, 2012 shares | Jan. 02, 2021 USD ($) shares | Sep. 26, 2020 | Sep. 26, 2020 | Jun. 27, 2020 | Mar. 28, 2020 USD ($) | Mar. 30, 2019 USD ($) | Jan. 02, 2021 USD ($) $ / shares shares | Dec. 28, 2019 USD ($) $ / shares shares | Dec. 31, 2018 USD ($) | Dec. 29, 2018 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  |  |  | 4 years |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  |  |  | $ 40,372 | $ 18,899 | $ 13,646 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) | shares |  |  |  |  |  |  |  |  | 0 | 0 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value |  |  |  |  |  |  |  |  | $ 21,500 | $ 17,800 |  | $ 6,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  | $ 2.73 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  | $ 6.62 | $ 1.69 |  | $ 1.50
Employee and Director Stock Options [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount |  |  | $ 1,000 |  |  |  |  |  | $ 1,000 |  |  |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  |  |  |  |  |  |  | 8 months 12 days |  |  |
Share-based Payment Arrangement, Option [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  |  |  | $ 2,000 | $ 2,400 |  | $ 4,100
Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  | $ 26.48 |  |  |
Chief Executive Officer [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  |  | $ 1,400 |  |  |  |
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  | 3 years |  |  |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  |  |  | $ 16,600 | 10,300 |  | 8,000
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount |  |  | $ 44,300 |  |  |  |  |  | $ 44,300 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Grants Tested Each Year |  |  |  |  |  |  | 50.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  | $ 1,800 |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Payment Arrangement, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  | 75.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Payment Arrangement, Tranche Two [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  | 100.00% |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  | 55.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Payment Arrangement, Tranche Three [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  | 25.00% |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  |  |  | 0.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Minimum [Member] | TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  | 250.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Minimum [Member] | Share-based Payment Arrangement, Tranche Three [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  | 25.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Maximum [Member] | TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  | 200.00% |  |  |  |  |
Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | Maximum [Member] | Share-based Payment Arrangement, Tranche Three [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  | 75.00% |  |  |  |  |
Executive Officer [Member] | Performance Shares [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  |  |  | 3 years |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  |  |  | $ 20,800 | $ 5,700 |  | $ 900
Executive Officer [Member] | Performance Shares [Member] | TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  |  |  | 100.00% |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  |  |  |  |  |  |  | 50.00% |  |  |
Executive Officer [Member] | Performance Shares [Member] | TSR Relative To PHLX Semiconductor Sector Index, 25th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  |  |  | 0.00% |  |  |
Executive Officer [Member] | Performance Shares [Member] | Minimum [Member] | TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  |  |  | 200.00% |  |  |
Executive Officer [Member] | Performance Shares [Member] | Minimum [Member] | TSR Relative To PHLX Semiconductor Sector Index, 25th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  |  |  | 0.00% |  |  |
Executive Officer [Member] | Performance Shares [Member] | Maximum [Member] | TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  |  |  |  | 250.00% |  |  |
Executive Officer [Member] | Performance Shares Granted in 2018 [Member] | Share-based Payment Arrangement, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  |  | 33.30% | 200.00% |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved |  |  | 75.00% | 75.00% |  |  | 75.00% |  |  |  |  |
Executive Officer [Member] | Performance Shares Granted in 2018 [Member] | Minimum [Member] | Share-based Payment Arrangement, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  | 250.00% |  |  |  |  |  |  |
Executive Officer [Member] | Performance Shares Granted in 2018 [Member] | Maximum [Member] | Share-based Payment Arrangement, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions |  |  |  |  | 200.00% |  |  |  |  |  |  |
The2012 ESPP [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares | 3.0 | 3.0 |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement By Share-based Payment Award, Maximum, Annual Contribution Per Employee, Percent | 10.00% |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent |  | 85.00% |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) | shares |  |  | 1,200,000 |  |  |  |  |  | 1,200,000 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number Of Shares, Transferred Out (in shares) | shares |  |  |  |  |  |  |  |  | 2,000,000.0 |  |  |
The 2013 Incentive Plan [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) | shares |  |  | 11,600,000 |  |  |  |  |  | 11,600,000 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Share Ratio |  |  | 2.2 |  |  |  |  |  | 2.2 |  |  |

X
- Definition Percentage of vesting of award under share-based payment arrangement based on market conditions. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageBasedOnMarketConditions
Namespace Prefix: | lscc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The yearly percentage of grants tested for award vesting rights under share based payment arrangement. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageOfGrantsTestedEachYear
Namespace Prefix: | lscc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of market condition achieved for awards to vest under share based payment arrangement. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageOfMarketConditionAchieved
Namespace Prefix: | lscc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum annual contribution percentage per employee that can be used under the plan. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardMaximumAnnualContributionPerEmployeePercent
Namespace Prefix: | lscc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares transferred out under the share-based compensation arrangement. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardNumberOfSharesTransferredOut
Namespace Prefix: | lscc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents share ratio of share-based compensation arrangement by share-based payment award. + References No definition available. + Details
Name: | lscc_SharebasedCompensationArrangementBySharebasedPaymentAwardShareRatio
Namespace Prefix: | lscc_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cost to be recognized for option under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares authorized for issuance under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of vesting of award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase price of common stock expressed as a percentage of its fair value. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=lscc_EmployeeAndDirectorStockOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=srt_ChiefExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=srt_ExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=lscc_TsrRelativeToPhlxSemiconductorSectorIndex75thPercentileMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=lscc_TsrRelativeToPhlxSemiconductorSectorIndex25thPercentileMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=lscc_PerformanceSharesGrantedIn2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=lscc_The2012ESPPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=lscc_The2013IncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |