Finance Receivables and Loans, Net (Schedule of Pass And Criticized Credit Quality Indicators of Finance Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 128,231	$ 129,926
Commercial portfolio segment
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	38,307	42,686
Commercial portfolio segment | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	34,080	38,710
Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,227	3,976
Commercial portfolio segment | Automotive loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	28,332	33,672
Commercial portfolio segment | Automotive loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	25,235	30,799
Commercial portfolio segment | Automotive loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	3,097	2,873
Commercial portfolio segment | Other loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	5,014	4,205
Commercial portfolio segment | Other loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,225	3,373
Commercial portfolio segment | Other loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	789	832
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,961	4,809
Commercial portfolio segment | Real estate-backed loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,620	4,538
Commercial portfolio segment | Real estate-backed loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 341	$ 271