XML 61 R50.htm IDEA: XBRL DOCUMENT
v3.20.2

Inventories - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Jun. 28, 2020 | Sep. 27, 2020 | Sep. 29, 2019
Inventory Disclosure [Abstract] |  |  |
Excess and obsolete inventory charges | $ 7,718 | $ 9,386 | $ 4,121

X
- Definition Excess and Obsolete Inventory Charges + References No definition available. + Details
Name: | cgnx_ExcessAndObsoleteInventoryCharges
Namespace Prefix: | cgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InventoryDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration