Finance Receivables and Loans, Net - Schedule of Past Due Financing Receivables and Loans Commercial (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 143,673	$ 137,454
Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	39,529	36,314
Commercial \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	47	73
Commercial \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	25	0
Commercial \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	20	0
Commercial \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	73
Commercial \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	39,482	36,241
Commercial \| Consumer automotive
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	20,597	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	20,597	18,339
Commercial \| Other
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	11,039	10,309
Commercial \| Other \| Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	45	70
Commercial \| Other \| 30–59 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	25	0
Commercial \| Other \| 60–89 days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	20	0
Commercial \| Other \| 90 or more days past due
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	70
Commercial \| Other \| Current
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	10,994	10,239
Commercial \| Commercial real estate
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	7,893	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	$ 7,891	$ 7,663