v3.25.2
Related-Party Transactions - Narrative (Details) - USD ($)
6 Months Ended
Jan. 01, 2023
Jun. 30, 2025
Dec. 31, 2024
Jun. 30, 2024
Sep. 30, 2023
Related Party Transaction [Line Items]          
Restricted cash and cash equivalents   $ 190,286,000 $ 128,061,000 $ 194,586,000  
Contract liabilities   $ 50,936,000 47,239,000    
State Farm Term Loan | 2025 JPM Credit Facility          
Related Party Transaction [Line Items]          
Fixed rate         8.00%
State Farm Term Loan | 2025 JPM Credit Facility | Hagerty Reinsurance Ltd          
Related Party Transaction [Line Items]          
Debt face amount         $ 25,000,000
Reinsurance Agreement | Affiliated Entity          
Related Party Transaction [Line Items]          
Reinsured risk, percentage 100.00% 80.00%      
Reinsured risk, ceded, percentage   50.00%      
Reinsurance Agreement | Affiliated Entity | Evanston          
Related Party Transaction [Line Items]          
Restricted cash and cash equivalents   $ 584,300,000 $ 589,200,000    
Alliance Agreement | Affiliated Entity | State Farm          
Related Party Transaction [Line Items]          
Related party transaction, transaction term   10 years      
Contract liabilities   $ 20,000,000.0