Fair Value Measurements - Schedule of Fair Value of the Debt Facilities (Details) - Level 2 - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	$ 18,300	$ 17,203
Aggregate Fair Value	15,800	16,484
Other Non-Vehicle Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	6,273	5,524
Aggregate Fair Value	3,732	4,822
Other Non-Vehicle Debt \| Exchangeable Notes Due 2029
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	294	271
Aggregate Fair Value	97	311
Other Non-Vehicle Debt \| Exchangeable Notes Due 2030
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	425	425
Aggregate Fair Value	113	324
Other Non-Vehicle Debt \| Exchangeable First Lien Notes Due 2030
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	380	0
Aggregate Fair Value	262	0
Other Non-Vehicle Debt \| Other Non-Vehicle Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	5,174	4,828
Aggregate Fair Value	3,260	4,187
Vehicle Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	12,027	11,679
Aggregate Fair Value	$ 12,068	$ 11,662