Fair Value Measurements - Schedule of Fair Value of the Debt Facilities (Details) - Level 2 - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	$ 19,080	$ 17,203
Aggregate Fair Value	17,109	16,484
Other Non-Vehicle Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	6,303	5,524
Aggregate Fair Value	4,297	4,822
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	5,246	4,828
Aggregate Fair Value	3,729	4,187
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	282	271
Aggregate Fair Value	127	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	136	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	350	0
Aggregate Fair Value	305	0
Vehicle Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nominal Unpaid Principal Balance	12,777	11,679
Aggregate Fair Value	$ 12,812	$ 11,662