Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 139,439	$ 135,748
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,820	2,915
Year two, originated, fiscal year before current fiscal year	2,845	2,035
Year three, originated, two years before current fiscal year	1,929	1,871
Year four, originated, three years before current fiscal year	1,597	1,406
Year five, originated, four years before current fiscal year	1,002	508
Originated, more than five years before current fiscal year	1,223	1,196
Revolving loans	23,811	19,057
Revolving loans converted to term	235	150
Total finance receivables and loans	34,462	29,138
Automotive | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	515	663
Year two, originated, fiscal year before current fiscal year	520	258
Year three, originated, two years before current fiscal year	195	132
Year four, originated, three years before current fiscal year	98	79
Year five, originated, four years before current fiscal year	59	38
Originated, more than five years before current fiscal year	37	55
Revolving loans	17,276	13,370
Revolving loans converted to term	0	0
Total finance receivables and loans	18,700	14,595
Automotive | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	509	640
Year two, originated, fiscal year before current fiscal year	512	211
Year three, originated, two years before current fiscal year	165	132
Year four, originated, three years before current fiscal year	97	78
Year five, originated, four years before current fiscal year	58	28
Originated, more than five years before current fiscal year	22	34
Revolving loans	16,446	12,327
Revolving loans converted to term	0	0
Total finance receivables and loans	17,809	13,450
Automotive | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	6	23
Year two, originated, fiscal year before current fiscal year	7	47
Year three, originated, two years before current fiscal year	30	0
Year four, originated, three years before current fiscal year	1	0
Year five, originated, four years before current fiscal year	1	10
Originated, more than five years before current fiscal year	14	21
Revolving loans	723	1,016
Revolving loans converted to term	0	0
Total finance receivables and loans	782	1,117
Automotive | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	1	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	1
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	44	27
Revolving loans converted to term	0	0
Total finance receivables and loans	45	28
Automotive | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0
Year two, originated, fiscal year before current fiscal year	0
Year three, originated, two years before current fiscal year	0
Year four, originated, three years before current fiscal year	0
Year five, originated, four years before current fiscal year	0
Originated, more than five years before current fiscal year	1
Revolving loans	63
Revolving loans converted to term	0
Total finance receivables and loans	64
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	331	771
Year two, originated, fiscal year before current fiscal year	854	627
Year three, originated, two years before current fiscal year	577	786
Year four, originated, three years before current fiscal year	614	629
Year five, originated, four years before current fiscal year	318	101
Originated, more than five years before current fiscal year	374	425
Revolving loans	6,435	5,678
Revolving loans converted to term	209	137
Total finance receivables and loans	9,712	9,154
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	331	594
Year two, originated, fiscal year before current fiscal year	646	469
Year three, originated, two years before current fiscal year	343	607
Year four, originated, three years before current fiscal year	405	419
Year five, originated, four years before current fiscal year	266	54
Originated, more than five years before current fiscal year	180	133
Revolving loans	6,202	5,344
Revolving loans converted to term	173	89
Total finance receivables and loans	8,546	7,709
Other | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	177
Year two, originated, fiscal year before current fiscal year	208	158
Year three, originated, two years before current fiscal year	188	175
Year four, originated, three years before current fiscal year	206	95
Year five, originated, four years before current fiscal year	51	47
Originated, more than five years before current fiscal year	85	128
Revolving loans	198	278
Revolving loans converted to term	25	35
Total finance receivables and loans	961	1,093
Other | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	46	4
Year four, originated, three years before current fiscal year	3	51
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	83	139
Revolving loans	25	55
Revolving loans converted to term	11	13
Total finance receivables and loans	168	262
Other | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	64
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	26	25
Revolving loans	10	0
Revolving loans converted to term	0	0
Total finance receivables and loans	36	89
Other | Loss | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	1	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	1
Revolving loans converted to term	0	0
Total finance receivables and loans	1	1
Commercial real estate | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	974	1,481
Year two, originated, fiscal year before current fiscal year	1,471	1,150
Year three, originated, two years before current fiscal year	1,157	953
Year four, originated, three years before current fiscal year	885	698
Year five, originated, four years before current fiscal year	625	369
Originated, more than five years before current fiscal year	812	716
Revolving loans	100	9
Revolving loans converted to term	26	13
Total finance receivables and loans	6,050	5,389
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	971	1,481
Year two, originated, fiscal year before current fiscal year	1,452	1,118
Year three, originated, two years before current fiscal year	1,129	951
Year four, originated, three years before current fiscal year	884	679
Year five, originated, four years before current fiscal year	607	369
Originated, more than five years before current fiscal year	811	716
Revolving loans	100	9
Revolving loans converted to term	26	13
Total finance receivables and loans	5,980	5,336
Commercial real estate | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	3	0
Year two, originated, fiscal year before current fiscal year	16	32
Year three, originated, two years before current fiscal year	28	2
Year four, originated, three years before current fiscal year	1	19
Year five, originated, four years before current fiscal year	18	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	66	$ 53
Commercial real estate | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0
Year two, originated, fiscal year before current fiscal year	3
Year three, originated, two years before current fiscal year	0
Year four, originated, three years before current fiscal year	0
Year five, originated, four years before current fiscal year	0
Originated, more than five years before current fiscal year	1
Revolving loans	0
Revolving loans converted to term	0
Total finance receivables and loans	$ 4