Securitizations and Variable Interest Entities - Schedule of Cash Flows with Nonconsolidated Special-Purpose Entities (Details) - Off-balance sheet variable interest entities - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Total	$ 227	$ 1,319
Automotive | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	191	1,281
Servicing fees	14	14
Cash flows received on retained interests in securitization entities	12	9
Other cash flows	1	1
Consumer other | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	8	12
Servicing fees	$ 1	$ 2