Securitizations and Variable Interest Entities - Schedule of Cash Flows with Nonconsolidated Special-Purpose Entities (Details) - Off-balance sheet variable interest entities - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Total	$ 1,761	$ 1,280	$ 389
Automotive | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	1,594	1,131	238
Servicing fees	58	19	1
Cash flows received on retained interests in securitization entities	54	4	0
Other cash flows	2	1	0
Cash disbursements for repurchases during the period	1	0	0
Consumer other | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	46	117	137
Servicing fees	$ 6	$ 8	$ 13