v3.26.3
VIEs - Narrative (Details)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
class
Sep. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Variable Interest Entity [Line Items]          
Number of classes of notes payable backed by collateral | class     1    
Amount securitized in off-balance sheet transaction     $ 3,800.0    
Value of securitization retained $ 143.0   143.0    
SBNA Auto Lease Trust (SBALT) | Structured LLC          
Variable Interest Entity [Line Items]          
Joint venture, acquired amount 7,500.0   7,500.0    
Fee income 13.0 $ 14.0 39.0 $ 42.0  
VIEs, Primary Beneficiary | Trusts          
Variable Interest Entity [Line Items]          
Gross retail installment contracts transferred to consolidated trusts 15,900.0   15,900.0   $ 25,100.0
VIE, Not Primary Beneficiary          
Variable Interest Entity [Line Items]          
Total serviced for other portfolio 1,200.0   1,200.0   2,000.0
VIE, Not Primary Beneficiary | Debt          
Variable Interest Entity [Line Items]          
VIE, maximum exposure to loss 708.0   708.0   1,000.0
VIE, Not Primary Beneficiary | Equity Investments          
Variable Interest Entity [Line Items]          
VIE, maximum exposure to loss $ 3.0   $ 3.0   $ 4.0