v3.25.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2025
Jul. 18, 2025
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Trading Symbol THRM  
Entity Registrant Name GENTHERM INCORPORATED  
Entity Central Index Key 0000903129  
Entity Current Reporting Status Yes  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   30,519,826
Entity Shell Company false  
Entity File Number 0-21810  
Entity Tax Identification Number 95-4318554  
Entity Address, Address Line One 28875 Cabot Drive  
Entity Address, City or Town Novi  
Entity Address, State or Province MI  
Entity Address, Postal Zip Code 48377  
City Area Code 248  
Local Phone Number 504-0500  
Entity Interactive Data Current Yes  
Entity Incorporation, State or Country Code MI  
Document Quarterly Report true  
Security Exchange Name NASDAQ  
Title of 12(b) Security Common Stock, no par value  
Document Transition Report false