XML 65 R20.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Other Current Liabilities (Policies) | 9 Months Ended
--- | ---
Sep. 25, 2015
Accrued Liabilities, Current [Abstract] |
Product Warranty Policy | A liability is established for estimated future warranty and service claims that relate to current and prior period sales. The Company estimates warranty costs based on historical claim experience and other factors including evaluating specific product warranty issues.

X
- Definition Disclosure of accounting policy for warranties including the methodology for measuring the liability. + References No definition available. + Details
Name: | ggg_ProductWarrantyPolicyTextBlock
Namespace Prefix: | ggg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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