XML 111 R97.htm IDEA: XBRL DOCUMENT
v3.20.4

Income Taxes - Additional Information (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Tax Credit Carryforward [Line Items] |  |  |
Discrete tax expense for migration of acquired intellectual property | 0.00% | 18.00% | 0.00%
Reserve for tax uncertainties | $ 13,952,000 | $ 11,591,000 | $ 7,294,000
Discrete tax benefit for changes to international tax structure |  | 87,500,000 |
Foreign tax structure deferred tax asset |  | 437,500,000 |
GILTI tax basis differences | 339,325,000 | 350,000,000 |
Domestic income from continuing operations before taxes | 39,425,000 | 31,396,000 | 39,042,000
Foreign income from continuing operations before taxes | $ 147,486,000 | $ 131,598,000 | $ 195,532,000
Income tax rate | 21.00% | 21.00% | 21.00%
Cash | $ 266,609,000 | $ 155,498,000 |
Foreign tax rate differential | 6.00% | 9.00% | 9.00%
Reduction of income tax expense for adoption of ASU 2016-09 | $ 12,788,000 | $ 6,472,000 | $ 8,488,000
Discrete tax benefit related to employee stock option exercises | 7.00% | 4.00% | 4.00%
Net cash provided by operating activities | $ 242,400,000 | $ 253,311,000 | $ 223,454,000
Net cash used in financing activities | 316,868,000 | 32,233,000 | 209,904,000
Income tax penalties and interest expense | 340,000 | 116,000 | 91,000
Reserve for income taxes | 14,257,000 | 11,563,000 |
Unrecognized tax benefit shown as a reduction to noncurrent deferred tax assets | 1,028,000 | 1,028,000 |
Interest and penalties, gross | 1,332,000 | 1,000,000 |
Minimum decrease in income tax expense due to release in reserves | 1,900,000 |  |
Maximum decrease in income tax expense due to release in reserves | 2,000,000 |  |
Deferred tax assets, valuation allowance | 8,568,000 | 7,312,000 |
Income tax paid net | 33,695,000 | 13,443,000 | 41,430,000
Effective income tax rate reconciliation, tax settlement, other, amount | 307,000 | 1,932,000 | 1,847,000
Tax cuts and jobs act, measurement period adjustment, income tax expense (benefit) |  |  | 3,240,000
Tax cuts and jobs act, transition tax for accumulated foreign earnings, income tax expense |  |  | 11,028,000
Tax cuts and jobs act, transition tax for accumulated foreign earnings, liability |  |  | $ 90,351,000
Deferred tax liabilities |  | 332,344,000 |
Unrecognized Tax Benefits, Gross | 15,285,000 | 12,591,000 |
Foreign Tax Benefit - Gains Taxed Outside U.S. [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
1. Effective income tax rate reconciliation, tax settlement, foreign, amount | 13,984,000 |  |
Foreign Tax Expense - Transfer Price Adjustment [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
1. Effective income tax rate reconciliation, tax settlement, foreign, amount | 3,267,000 |  |
Discrete Tax Expense - Foreign Tax Filing Adjustments [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
1. Effective income tax rate reconciliation, tax settlement, foreign, amount | 843,000 |  |
Research Tax Credit Carryforward [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Deferred tax assets, valuation allowance | 8,568,000 |  |
State Research And Experimentation [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Deferred tax assets, tax credit carryforwards, research | $ 11,361,000 |  |
Foreign Tax Authority [Member] | Revenue Commissioners, Ireland [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Income tax rate | 12.50% |  |
Foreign Tax Authority [Member] | State Administration of Taxation, China [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Income tax rate | 25.00% |  |
Domestic Tax Authority [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Income tax rate | 21.00% |  |
Sualab Co., Ltd. [Member] |  |  |
Tax Credit Carryforward [Line Items] |  |  |
Reserve for tax uncertainties |  | 3,700,000 |
Effective Income Tax Rate Reconciliation, Migration of Acquired Intellectual Property Dollar |  | $ 28,528,000 |

X
- Definition Deferred Tax Assets, Foreign Tax Structure Change + References No definition available. + Details
Name: | cgnx_DeferredTaxAssetsForeignTaxStructureChange
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred Tax Liabilities, Tax Cuts And Jobs Act, Global Intangible Low Tax Income + References No definition available. + Details
Name: | cgnx_DeferredTaxLiabilitiesTaxCutsAndJobsActGlobalIntangibleLowTaxIncome
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective Income Tax Rate Reconciliation, Migration of Acquired Intellectual Property Dollar + References No definition available. + Details
Name: | cgnx_EffectiveIncomeTaxRateReconciliationMigrationOfAcquiredIntellectualPropertyDollar
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Migration of Acquired Intellectual Property + References No definition available. + Details
Name: | cgnx_EffectiveIncomeTaxRateReconciliationMigrationofAcquiredIntellectualProperty
Namespace Prefix: | cgnx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum decrease in income tax expense due to release in reserves. + References No definition available. + Details
Name: | cgnx_MaximumDecreaseInIncomeTaxExpenseDueToReleaseInReserves
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Minimum decrease in income tax expense due to release in reserves. + References No definition available. + Details
Name: | cgnx_MinimumDecreaseInIncomeTaxExpenseDueToReleaseInReserves
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Unrecognized Tax Benefits, Gross + References No definition available. + Details
Name: | cgnx_UnrecognizedTaxBenefitsGross
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unrecognized tax benefit shown as a reduction to noncurrent deferred tax assets as a result of net operating loss carryforward, a similar tax loss, or a tax credit carryforward. + References No definition available. + Details
Name: | cgnx_Unrecognizedtaxbenefitshownasareductiontononcurrentdeferredtaxassets
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=118262064&loc=SL116631418-115840 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 45 -Paragraph 21 -URI http://asc.fasb.org/extlink&oid=118262064&loc=SL116631419-115840 + Details
Name: | us-gaap_Cash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(15)(b)(2)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(15)(2)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DeferredIncomeTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible research tax credit carryforwards. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 740 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120384911&loc=d3e23163-113944 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 740 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120384911&loc=d3e23163-113944 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.3) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.3) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax settlement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_IncomeTaxReconciliationTaxSettlementsForeign
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other income tax settlements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_IncomeTaxReconciliationTaxSettlementsOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4297-108586 + Details
Name: | us-gaap_IncomeTaxesPaidNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount recognized for uncertainty in income taxes classified as noncurrent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LiabilityForUncertainTaxPositionsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3521-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3536-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3521-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInOperatingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_TaxCreditCarryforwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of income tax expense (benefit) for measurement period adjustment from accounting for tax effect pursuant to Tax Cuts and Jobs Act. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 2A -Subparagraph (SAB Topic 5.EE.Q2(f)) -URI http://asc.fasb.org/extlink&oid=116825942&loc=SL116722634-122817 + Details
Name: | us-gaap_TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of income tax expense from transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319 + Details
Name: | us-gaap_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of tax liability from transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -URI http://asc.fasb.org/topic&trid=2144680 + Details
Name: | us-gaap_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=120406818&loc=SL37586934-109318 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | cgnx_DiscreteTaxItemsAxis=cgnx_ForeignTaxBenefitGainsTaxedOutsideUSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | cgnx_DiscreteTaxItemsAxis=cgnx_ForeignTaxExpenseTransferPriceAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | cgnx_DiscreteTaxItemsAxis=cgnx_DiscreteTaxExpenseForeignTaxFilingAdjustmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=us-gaap_ResearchMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=cgnx_StateResearchAndExperimentationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_ForeignCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_RevenueCommissionersIrelandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_StateAdministrationOfTaxationChinaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=cgnx_SualabCo.Ltd.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |