Finance Receivables and Loans, Net - Schedule of Past Due Financing Receivables and Loans Commercial (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 136,030	$ 139,439
Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	32,745	34,462
Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,259	18,700
Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	8,212	9,712
Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	6,274	6,050
Total past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	42	5
Total past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	5	0
Total past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	35	5
Total past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	0
30–59 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	41	2
30–59 days past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	5	0
30–59 days past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	35	2
30–59 days past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	1	0
60–89 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
60–89 days past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
60–89 days past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
60–89 days past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
90 or more days past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	1	3
90 or more days past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
90 or more days past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	3
90 or more days past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	1	0
Current | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	32,703	34,457
Current | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,254	18,700
Current | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	8,177	9,707
Current | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 6,272	$ 6,050