Debt - ABS Financing Facilities (Details) $ in Millions	1 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Apr. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Feb. 28, 2025 USD ($)	Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jun. 30, 2025 USD ($) agreement	Jun. 30, 2024 USD ($)
Debt Instrument [Line Items]
Proceeds from asset-backed long-term borrowings							$ 4,962	$ 5,828
Repayments of debt					$ 2,158	$ 1,978	4,136
Retained Notes
Debt Instrument [Line Items]
Proceeds from asset-backed long-term borrowings					129		$ 129
2021 ABS Financing Facility | Secured Debt
Debt Instrument [Line Items]
Number of loan agreements | agreement							2
Repayments of debt	$ 100		$ 1,400	$ 250
Amount drawn from credit facilities		$ 1,100
Debt outstanding	7,400				7,400		$ 7,400
2022 ABS Financing Facility | Secured Debt
Debt Instrument [Line Items]
Repayments of debt		$ 241		$ 163
Amount drawn from credit facilities			$ 189
Debt outstanding	$ 4,800				$ 4,800		$ 4,800