v3.26.1
Stock-Based Compensation Plans - Narrative (Details)
$ in Millions
3 Months Ended
Jul. 01, 2022
shares
Mar. 31, 2026
USD ($)
plan
shares
Mar. 31, 2025
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense for share-based payments   $ 10.4 $ 8.7
2019 Omnibus Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share awards made (in shares) | shares   13,241,091  
Shares granted (in shares) | shares   38,942,701  
Shares available to be issued (in shares) | shares   45,000,000  
Employee Stock Option Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost   $ 3.3  
Employee Stock Option Plan | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period   1 year  
Award expiration period   5 years  
Employee Stock Option Plan | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period   5 years  
Award expiration period   10 years  
Second Restricted Stock Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost   $ 54.1  
Maximum restricted period   10 years  
Restricted compensation expense   $ 6.0 5.9
2022 Gentex Corporation Employee Stock Purchase Plan | Employee Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares granted (in shares) | shares   804,112  
Shares available to be issued (in shares) | shares 2,000,000    
ESPP discount rate 85.00%    
ESPP discount rate recognized as compensation expense 15.00%    
Stock Compensation Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of plans | plan   2  
Performance Shares      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense for share-based payments   $ 2.9 1.0
Unrecognized compensation cost   $ 17.6  
Performance Shares | 2019 Omnibus Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares granted (in shares) | shares   7,074,664  
Performance Share Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense for share-based payments   $ 0.5 $ 0.5
Award vesting period   4 years