XML 78 R64.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Cash, Cash Equivalents and Investments - Amortized Cost to Fair Value (Detail) $ in Thousands | Dec. 31, 2018 USD ($)
--- | ---
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | $ 691,319
Gross Unrealized Gains | 323
Gross Unrealized Losses | (2,255)
Fair Value, Total | 689,387
Treasury Bills [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 231,237
Treasury Bills [Member] | Short-term Investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 198,512
Gross Unrealized Gains | 38
Gross Unrealized Losses | (73)
Fair Value, Total | 198,477
Treasury Bills [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 32,722
Gross Unrealized Gains | 51
Gross Unrealized Losses | (13)
Fair Value, Total | 32,760
Corporate Bonds [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 300,437
Corporate Bonds [Member] | Short-term Investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 138,219
Gross Unrealized Gains | 27
Gross Unrealized Losses | (375)
Fair Value, Total | 137,871
Corporate Bonds [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 163,847
Gross Unrealized Gains | 107
Gross Unrealized Losses | (1,388)
Fair Value, Total | 162,566
Asset-Backed Securities [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 132,038
Asset-Backed Securities [Member] | Short-term Investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 78,628
Gross Unrealized Gains | 15
Gross Unrealized Losses | (236)
Fair Value, Total | 78,407
Asset-Backed Securities [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 53,693
Gross Unrealized Gains | 55
Gross Unrealized Losses | (117)
Fair Value, Total | 53,631
Sovereign Bonds [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 14,417
Sovereign Bonds [Member] | Short-term Investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 8,135
Gross Unrealized Gains | 0
Gross Unrealized Losses | (34)
Fair Value, Total | 8,101
Sovereign Bonds [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 6,286
Gross Unrealized Gains | 30
Gross Unrealized Losses | 0
Fair Value, Total | 6,316
Agency Bonds [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 5,921
Agency Bonds [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 5,930
Gross Unrealized Gains | 0
Gross Unrealized Losses | (9)
Fair Value, Total | 5,921
Municipal Bonds [Member] |
Debt Securities, Available-for-sale [Line Items] |
Fair Value, Total | 5,337
Municipal Bonds [Member] | Short-term Investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 4,492
Gross Unrealized Gains | 0
Gross Unrealized Losses | 0
Fair Value, Total | 4,492
Municipal Bonds [Member] | Long-term investments [Member] |
Debt Securities, Available-for-sale [Line Items] |
Amortized Cost | 855
Gross Unrealized Gains | 0
Gross Unrealized Losses | (10)
Fair Value, Total | $ 845

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=cgnx_LongTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_SovereignDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cgnx_AgencyBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |