XML 22 R43.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Contingencies - Narrative (Details) (Pending Litigation [Member]) | 0 Months Ended |  |
--- | --- | --- | ---
Jun. 25, 2012 co-defendant complaint | Oct. 05, 2012 complaint | Jul. 27, 2012 complaint
Loss Contingencies [Line Items] |  |  |
Number of complaints filed | 4 |  |
Number of Co-defendants | 1 |  |
Total number of customers cited as possible co-defendants | 2 |  |
Number of complaints served |  |  | 4
Number of complaints answered |  | 4 |
SmartBeam [Member] |  |  |
Loss Contingencies [Line Items] |  |  |
Number of complaints filed | 2 |  |
Number of patents infringed upon | 1 |  |
Monitoring System Products [Member] |  |  |
Loss Contingencies [Line Items] |  |  |
Number of complaints filed | 2 |  |
Number of patents infringed upon | 2 |  |

X
- Definition Loss Contingency, Number of Co-defendants + References No definition available. + Details
Name: | gntx_LossContingencyNumberOfCoDefendants
Namespace Prefix: | gntx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loss Contingency, Number of Complaints Answered + References No definition available. + Details
Name: | gntx_LossContingencyNumberOfComplaintsAnswered
Namespace Prefix: | gntx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loss Contingency, Number of Complaints Served + References No definition available. + Details
Name: | gntx_LossContingencyNumberOfComplaintsServed
Namespace Prefix: | gntx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loss Contingency, Number of Patents Infringed + References No definition available. + Details
Name: | gntx_LossContingencyNumberOfPatentsInfringed
Namespace Prefix: | gntx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loss Contingency, Total Number of Customers cited as Possible Co-defendants + References No definition available. + Details
Name: | gntx_LossContingencyTotalNumberOfCustomersCitedAsPossibleCoDefendants
Namespace Prefix: | gntx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total number of new claims filed pertaining to a loss contingency during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9, 10, 11, 12 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration