Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 136,304	$ 135,748
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	475	2,915
Year two, originated, fiscal year before current fiscal year	2,958	2,035
Year three, originated, two years before current fiscal year	1,989	1,871
Year four, originated, three years before current fiscal year	1,594	1,406
Year five, originated, four years before current fiscal year	1,290	508
Originated, more than five years before current fiscal year	1,538	1,196
Revolving loans	19,479	19,057
Revolving loans converted to term	166	150
Total finance receivables and loans	29,489	29,138
Automotive | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	130	663
Year two, originated, fiscal year before current fiscal year	620	258
Year three, originated, two years before current fiscal year	244	132
Year four, originated, three years before current fiscal year	122	79
Year five, originated, four years before current fiscal year	72	38
Originated, more than five years before current fiscal year	77	55
Revolving loans	13,640	13,370
Revolving loans converted to term	0	0
Total finance receivables and loans	14,905	14,595
Automotive | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	129	640
Year two, originated, fiscal year before current fiscal year	598	211
Year three, originated, two years before current fiscal year	198	132
Year four, originated, three years before current fiscal year	122	78
Year five, originated, four years before current fiscal year	72	28
Originated, more than five years before current fiscal year	50	34
Revolving loans	12,654	12,327
Revolving loans converted to term	0	0
Total finance receivables and loans	13,823	13,450
Automotive | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1	23
Year two, originated, fiscal year before current fiscal year	22	47
Year three, originated, two years before current fiscal year	46	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	10
Originated, more than five years before current fiscal year	27	21
Revolving loans	926	1,016
Revolving loans converted to term	0	0
Total finance receivables and loans	1,022	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	0	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	60	27
Revolving loans converted to term	0	0
Total finance receivables and loans	60	28
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	82	771
Year two, originated, fiscal year before current fiscal year	817	627
Year three, originated, two years before current fiscal year	623	786
Year four, originated, three years before current fiscal year	529	629
Year five, originated, four years before current fiscal year	527	101
Originated, more than five years before current fiscal year	523	425
Revolving loans	5,830	5,678
Revolving loans converted to term	144	137
Total finance receivables and loans	9,075	9,154
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	82	594
Year two, originated, fiscal year before current fiscal year	640	469
Year three, originated, two years before current fiscal year	436	607
Year four, originated, three years before current fiscal year	329	419
Year five, originated, four years before current fiscal year	319	54
Originated, more than five years before current fiscal year	170	133
Revolving loans	5,513	5,344
Revolving loans converted to term	93	89
Total finance receivables and loans	7,582	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	177	158
Year three, originated, two years before current fiscal year	187	175
Year four, originated, three years before current fiscal year	196	95
Year five, originated, four years before current fiscal year	95	47
Originated, more than five years before current fiscal year	209	128
Revolving loans	260	278
Revolving loans converted to term	38	35
Total finance receivables and loans	1,162	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	0	4
Year four, originated, three years before current fiscal year	4	51
Year five, originated, four years before current fiscal year	50	0
Originated, more than five years before current fiscal year	118	139
Revolving loans	55	55
Revolving loans converted to term	13	13
Total finance receivables and loans	240	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	63	0
Originated, more than five years before current fiscal year	26	25
Revolving loans	2	0
Revolving loans converted to term	0	0
Total finance receivables and loans	91	89
Other | Loss | 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		0
Revolving loans		1
Revolving loans converted to term		0
Total finance receivables and loans		1
Commercial real estate | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	263	1,481
Year two, originated, fiscal year before current fiscal year	1,521	1,150
Year three, originated, two years before current fiscal year	1,122	953
Year four, originated, three years before current fiscal year	943	698
Year five, originated, four years before current fiscal year	691	369
Originated, more than five years before current fiscal year	938	716
Revolving loans	9	9
Revolving loans converted to term	22	13
Total finance receivables and loans	5,509	5,389
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	263	1,481
Year two, originated, fiscal year before current fiscal year	1,519	1,118
Year three, originated, two years before current fiscal year	1,090	951
Year four, originated, three years before current fiscal year	941	679
Year five, originated, four years before current fiscal year	672	369
Originated, more than five years before current fiscal year	937	716
Revolving loans	9	9
Revolving loans converted to term	22	13
Total finance receivables and loans	5,453	5,336
Commercial real estate | Special mention | 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	2	32
Year three, originated, two years before current fiscal year	32	2
Year four, originated, three years before current fiscal year	2	19
Year five, originated, four years before current fiscal year	19	0
Originated, more than five years before current fiscal year	1	0
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 56	$ 53