Finance Receivables and Loans, Net - Schedule of Past Due Financing Receivables and Loans Commercial (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 139,890	$ 137,454
Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	37,917	36,314
Commercial \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	73	73
Commercial \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	73	73
Commercial \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	37,844	36,241
Commercial \| Consumer automotive
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,972	18,339
Commercial \| Consumer automotive \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Consumer automotive \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Consumer automotive \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Consumer automotive \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Consumer automotive \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,972	18,339
Commercial \| Other
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	11,093	10,309
Commercial \| Other \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	71	70
Commercial \| Other \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Other \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Other \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	71	70
Commercial \| Other \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	11,022	10,239
Commercial \| Commercial real estate
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	7,852	7,666
Commercial \| Commercial real estate \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	3
Commercial \| Commercial real estate \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Commercial real estate \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Commercial \| Commercial real estate \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	3
Commercial \| Commercial real estate \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 7,850	$ 7,663