Finance Receivables and Loans, Net (Past Due Financing Receivables and Loans Commercial) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 136,304	$ 135,748
Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	29,489	29,138
Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	14,905	14,595
Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	9,075	9,154
Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	5,509	5,389
Total past due | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	4	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	4	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	1	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	1	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	29,485	29,135
Current | Automotive | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	14,905	14,595
Current | Other | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	9,071	9,151
Current | Commercial real estate | Commercial
Financing Receivable, Past Due [Line Items]
Finance receivables and loans, net	$ 5,509	$ 5,389