v3.26.1
Stockholders' Equity - Schedule of Other Ownership Interests (Details) - shares
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Class of Stock [Roll Forward]          
Ending balance (in shares) 346,801,330 345,815,692 346,801,330 345,815,692  
Common stock, shares, issued (in shares) 346,801,330 345,815,692 346,801,330 345,815,692  
THG units held by Hagerty, Inc.          
Class of Stock [Roll Forward]          
Beginning of period 29.20% 26.10% 29.10% 26.10%  
End of period 29.40% 26.20% 29.40% 26.20%  
THG units held by other unit holders          
Class of Stock [Roll Forward]          
Beginning balance (in shares) 245,050,694 255,154,346 245,420,794 255,178,346  
Ending balance (in shares) 244,996,392 255,100,044 244,996,392 255,100,044  
Beginning of period 70.80% 73.90% 70.90% 73.90%  
End of period 70.60% 73.80% 70.60% 73.80%  
Class A Common Stock          
Class of Stock [Roll Forward]          
Beginning balance (in shares)     100,706,893    
Ending balance (in shares) 101,804,938   101,804,938    
Common stock, shares, issued (in shares) 101,804,938   101,804,938   100,706,893
Class A Common Stock | THG units held by Hagerty, Inc.          
Class of Stock [Roll Forward]          
Beginning balance (in shares) 101,085,283 90,064,663 100,706,893 90,032,391  
Issuance of shares under employee plans (in shares) 665,353 596,683 673,643 604,955  
Exchange of THG units for Class A Common Stock (in shares) (54,302) (54,302) (424,402) (78,302)  
Ending balance (in shares) 101,804,938 90,715,648 101,804,938 90,715,648  
Class A Common Stock | THG units held by other unit holders          
Class of Stock [Roll Forward]          
Exchange of THG units for Class A Common Stock (in shares) (54,302) (54,302) (424,402) (78,302)