XML 92 R60.htm IDEA: XBRL DOCUMENT v2.4.0.8

Goodwill - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013 Segment	Oct. 04, 2010 MVSD [Member]	Oct. 04, 2010 SISD [Member]
Goodwill [Line Items]
Number of reportable segments	2
Fair value in excess to carrying value		208.00%	119.00%

X

- Definition

Fair value in excess to carrying value.

+ References

No definition available.

+ Details

Name:	cgnx_FairValueInExcessToCarryingValue
Namespace Prefix:	cgnx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of reporting units for goodwill allocation.

+ References

No definition available.

+ Details

Name:	cgnx_NumberOfReportingUnitsForGoodwillAllocation
Namespace Prefix:	cgnx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_GoodwillLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration