Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2022	Feb. 01, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-10235
Entity Registrant Name	GENTEX CORPORATION
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-2030505
Entity Address, Address Line One	600 N. Centennial Street,
Entity Address, City or Town	Zeeland,
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	49464
City Area Code	616
Local Phone Number	772-1800
Title of 12(b) Security	Common Stock, par value $.06 per share
Trading Symbol	GNTX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 6,587,687,393
Entity Common Stock, Shares Outstanding		234,177,812
Documents Incorporated by Reference	Portions of the Company’s Proxy Statement for its 2023 Annual Meeting of Shareholders are incorporated by reference into Part III.
Entity Central Index Key	0000355811
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false