Stock-Based Compensation Plans (Narrative) (Details)		1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2022 shares	May 31, 2022 shares	Jun. 30, 2023 USD ($) plan shares	Jun. 30, 2022 USD ($) shares	Jun. 30, 2023 USD ($) plan shares	Jun. 30, 2022 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 9,744,670	$ 8,573,230	$ 18,264,205	$ 15,361,567
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					1,624,122
Number of shares authorized(in share)	2,000,000			2,000,000		2,000,000
ESPP discount rate	85.00%
ESPP discount rate recognized as compensation expense	15.00%
Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grants in period (in shares)					9,445,055
Shares issued under the omnibus plan (in shares)					23,954,574
Number of shares authorized(in share)			45,000,000		45,000,000
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost | $			$ 8,765,464		$ 8,765,464
Employee Stock Option Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period					1 year
Option expiration period					5 years
Employee Stock Option Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period					5 years
Option expiration period					10 years
Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost | $			47,040,485		$ 47,040,485
Restricted period, maximum					10 years
Amortization expense | $			$ 5,862,755	$ 5,335,072	$ 11,808,809	$ 10,625,877
Gentex Corporation Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					205,505
Number of shares authorized(in share)		2,000,000
ESPP discount rate		85.00%
ESPP discount rate recognized as compensation expense		15.00%
Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans | plan			2		2
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 1,635,022	$ 1,442,676	$ 2,137,228	$ 1,122,206
Unrecognized compensation cost | $			20,063,943		$ 20,063,943
Performance Shares | Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					3,507,089
Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 516,493		$ 641,218
Option vesting period					4 years