DEBT - Schedule of Non-Recourse Notes Payable (Details) - Non-recourse notes payable - Non-recourse $ in Millions	Sep. 30, 2025 USD ($)
Debt Instrument [Line Items]
Balance	$ 2,245.7
Initial Principal Amount	4,964.7
LAD Auto Receivables Trust 2021-1 Class A-D
Debt Instrument [Line Items]
Balance	14.6
Initial Principal Amount	$ 344.4
LAD Auto Receivables Trust 2021-1 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	3.99%
LAD Auto Receivables Trust 2021-1 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	3.99%
LAD Auto Receivables Trust 2022-1 Class A-C
Debt Instrument [Line Items]
Balance	$ 40.6
Initial Principal Amount	$ 298.1
LAD Auto Receivables Trust 2022-1 Class A-C \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.21%
LAD Auto Receivables Trust 2022-1 Class A-C \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	6.85%
LAD Auto Receivables Trust 2023-1 Class A-D
Debt Instrument [Line Items]
Balance	$ 92.5
Initial Principal Amount	$ 479.7
LAD Auto Receivables Trust 2023-1 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.48%
LAD Auto Receivables Trust 2023-1 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	7.30%
LAD Auto Receivables Trust 2023-2 Class A-D
Debt Instrument [Line Items]
Balance	$ 141.7
Initial Principal Amount	$ 556.7
LAD Auto Receivables Trust 2023-2 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.42%
LAD Auto Receivables Trust 2023-2 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	6.30%
LAD Auto Receivables Trust 2023-3 Class A-D
Debt Instrument [Line Items]
Balance	$ 135.6
Initial Principal Amount	$ 415.4
LAD Auto Receivables Trust 2023-3 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.95%
LAD Auto Receivables Trust 2023-3 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	6.92%
LAD Auto Receivables Trust 2023-4 Class A-D
Debt Instrument [Line Items]
Balance	$ 157.4
Initial Principal Amount	$ 421.2
LAD Auto Receivables Trust 2023-4 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	6.10%
LAD Auto Receivables Trust 2023-4 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	7.37%
LAD Auto Receivables Trust 2024-1 Class A-D
Debt Instrument [Line Items]
Balance	$ 144.1
Initial Principal Amount	$ 329.4
LAD Auto Receivables Trust 2024-1 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.17%
LAD Auto Receivables Trust 2024-1 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	6.15%
LAD Auto Receivables Trust 2024-2 Class A-D
Debt Instrument [Line Items]
Balance	$ 220.1
Initial Principal Amount	$ 409.6
LAD Auto Receivables Trust 2024-2 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	5.46%
LAD Auto Receivables Trust 2024-2 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	6.37%
LAD Auto Receivables Trust 2024-3 Class A-D
Debt Instrument [Line Items]
Balance	$ 388.1
Initial Principal Amount	$ 614.9
LAD Auto Receivables Trust 2024-3 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	4.52%
LAD Auto Receivables Trust 2024-3 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	5.18%
LAD Auto Receivables Trust 2025-1 Class A-D
Debt Instrument [Line Items]
Balance	$ 417.9
Initial Principal Amount	$ 564.0
LAD Auto Receivables Trust 2025-1 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	4.60%
LAD Auto Receivables Trust 2025-1 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	5.52%
LAD Auto Receivables Trust 2025-2 Class A-D
Debt Instrument [Line Items]
Balance	$ 493.1
Initial Principal Amount	$ 531.3
LAD Auto Receivables Trust 2025-2 Class A-D \| Minimum
Debt Instrument [Line Items]
Interest Rate Range	4.25%
LAD Auto Receivables Trust 2025-2 Class A-D \| Maximum
Debt Instrument [Line Items]
Interest Rate Range	5.01%