Finance Receivables and Loans, Net (Past Due Financing Receivables and Loans Commercial) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 139,439	$ 135,748
Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	34,462	29,138
Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,700	14,595
Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	9,712	9,154
Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	6,050	5,389
Total past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	5	3
Total past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Total past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	5	3
Total past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
30–59 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	0
30–59 days past due | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
30–59 days past due | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	2	0
30–59 days past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
60–89 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	1
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	1
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	3	2
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	3	2
90 or more days past due | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	0	0
Current | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	34,457	29,135
Current | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	18,700	14,595
Current | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	9,707	9,151
Current | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 6,050	$ 5,389