Securitizations and Variable Interest Entities - Schedule of Cash Flows with Nonconsolidated Special-Purpose Entities (Details) - Off-balance sheet variable interest entities - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Total	$ 1,472	$ 563
Automotive | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	1,387	477
Servicing fees	29	6
Cash flows received on retained interests in securitization entities	27	0
Other cash flows	1	0
Consumer other | Consumer
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash proceeds from transfers completed during the period	25	75
Servicing fees	$ 3	$ 5