XML 78 R65.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Revenue (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 1,731,169,929 | $ 1,688,189,405 | $ 1,858,897,406
Automotive Segment |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,697,188,034 | 1,648,198,143 |
Other |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 33,981,895 | 39,991,262 | 48,360,519
Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,697,188,034 | 1,648,198,143 | 1,810,536,887
Automotive Mirrors & Electronics | Automotive Segment |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 1,563,424,443 | 1,520,628,604 |
Automotive Mirrors & Electronics | Automotive Segment | Minimum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 15 days |  |
Automotive Mirrors & Electronics | Automotive Segment | Maximum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 90 days |  |
HomeLink Modules | Automotive Segment |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 133,763,591 | 127,569,539 |
Other Products (U.S.) | Other |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 33,981,895 | 39,991,262 | 48,360,519
Fire Protection Products | Other |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 25,048,697 | 22,716,985 |
Fire Protection Products | Other | Minimum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 30 days |  |
Fire Protection Products | Other | Maximum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 75 days |  |
Windows Products | Other |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 8,914,798 | 17,274,277 |
Nanofiber Products | Other |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 18,400 | 0 |
Dimmable Aircraft Windows | Other | Minimum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 30 days |  |
Dimmable Aircraft Windows | Other | Maximum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Payment terms (in days) | 45 days |  |
United States | Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 542,690,346 | 519,337,271 | 569,939,756
United States | Other Products (U.S.) |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 33,981,895 | 39,991,262 | 48,360,519
Germany | Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 234,994,551 | 228,652,827 | 296,276,971
Japan | Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 211,417,475 | 216,100,530 | 225,577,146
Mexico | Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 111,761,245 | 127,157,684 | 160,967,900
Other Countries | Automotive Products |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 596,324,417 | $ 556,949,831 | $ 557,775,114

X
- Definition Revenue from Contract with Customer, Payment Terms + References No definition available. + Details
Name: | gntx_RevenuefromContractwithCustomerPaymentTerms
Namespace Prefix: | gntx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 924 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856 + Details
Name: | us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gntx_AutomotiveSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_AllOtherSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_AutomotiveProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_AutomotiveMirrorsElectronicsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_HomeLinkModulesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_OtherProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_FireProtectionProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_WindowsProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_NanofiberProductsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gntx_DimmableAircraftWindowsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_DE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_JP
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_MX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=gntx_OtherCountriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |