v3.26.1
DEBT - Narrative (Details)
$ in Millions, $ in Millions
 6 Months Ended 12 Months Ended
Feb. 27, 2026
USD ($)
financeCompany
financialInstitution
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Dec. 31, 2025
Feb. 27, 2026
CAD ($)
financeCompany
financialInstitution
Debt Instrument [Line Items]          
Proceeds from issuance of non-recourse notes payable   $ 1,057.7 $ 564.0    
Non-recourse | Asset Backed Funding Vehicles          
Debt Instrument [Line Items]          
Proceeds from issuance of non-recourse notes payable   $ 1,057.7      
Syndicated Credit Facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility $ 6,500.0        
Syndicated Credit Facility | New vehicle floor plan          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility 2,700.0        
Syndicated Credit Facility | Used vehicle floor plan          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility 1,300.0        
Syndicated Credit Facility | Service loaner floor plan          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility 150.0        
Syndicated Credit Facility | Revolving line of credit          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility $ 2,400.0        
Option to reallocate commitment, maximum aggregate commitment threshold (as a percent) 50.00%       50.00%
Syndicated Credit Facility | Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, number of counter-parties | financialInstitution 18       18
Debt instrument, number of manufacturer-affiliated finance companies | financeCompany 6       6
Basis spread on variable rate (as a percent) 0.10%        
Syndicated Credit Facility | Line of Credit | Minimum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.40%        
Syndicated Credit Facility | Line of Credit | Maximum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.20%        
Syndicated Credit Facility | Line of Credit | New vehicle floor plan          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.10%        
Syndicated Credit Facility | Line of Credit | Used vehicle floor plan          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.20%        
Syndicated Credit Facility | Line of Credit | Service loaner floor plan          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.20%        
Syndicated Credit Facility | Line of Credit | Revolving line of credit | Minimum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.00%        
Syndicated Credit Facility | Line of Credit | Revolving line of credit | Maximum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 2.00%        
Syndicated Credit Facility, Upon Expansion of Original Line of Credit          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility $ 7,000.0        
Bank of Nova Scotia Credit Agreement          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         $ 1,100
Bank of Nova Scotia Credit Agreement | Working capital revolving facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         125
Bank of Nova Scotia Credit Agreement | Wholesale flooring facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         375
Bank of Nova Scotia Credit Agreement | Used vehicle flooring facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         100
Bank of Nova Scotia Credit Agreement | Wholesale leasing facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         500
Bank of Nova Scotia Credit Agreement | Daily rental facility          
Debt Instrument [Line Items]          
Credit facility, maximum borrowing facility         $ 25
Bank of Nova Scotia Credit Agreement | Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, number of counter-parties | financialInstitution 6       6
Debt instrument, number of manufacturer-affiliated finance companies | financeCompany 2       2
Basis spread on variable rate (as a percent) 0.30%        
Bank of Nova Scotia Credit Agreement | Line of Credit | Minimum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.25%        
Bank of Nova Scotia Credit Agreement | Line of Credit | Maximum          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 2.25%        
Bank of Nova Scotia Credit Agreement | Line of Credit | Used vehicle floor plan          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 1.10%     1.25%