Finance Receivables and Loans, Net - Schedule of Accounts, Notes, Loans and Financing Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	$ 136,030	$ 139,439
Unamortized premiums and discounts and deferred fees and costs	2,300	2,300
Accrued interest receivable	839	853
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	103,285	104,977
Consumer | Automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	83,757	84,320
Consumer | Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	17,234	18,667
Interest-only mortgage loans	12	15
Consumer | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	2,294	1,990
Consumer | Credit Card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	2,294	1,990
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	32,745	34,462
Commercial | Automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	18,259	18,700
Commercial | Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	6,274	6,050
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total finance receivables and loans	$ 8,212	$ 9,712