Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 138,449	$ 135,748
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	843	2,915
Year two, originated, fiscal year before current fiscal year	2,904	2,035
Year three, originated, two years before current fiscal year	2,001	1,871
Year four, originated, three years before current fiscal year	1,547	1,406
Year five, originated, four years before current fiscal year	1,193	508
Originated, more than five years before current fiscal year	1,470	1,196
Revolving loans	20,904	19,057
Revolving loans converted to term	217	150
Total finance receivables and loans	31,079	29,138
Automotive | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	273	663
Year two, originated, fiscal year before current fiscal year	580	258
Year three, originated, two years before current fiscal year	234	132
Year four, originated, three years before current fiscal year	112	79
Year five, originated, four years before current fiscal year	68	38
Originated, more than five years before current fiscal year	68	55
Revolving loans	14,958	13,370
Revolving loans converted to term	0	0
Total finance receivables and loans	16,293	14,595
Automotive | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	271	640
Year two, originated, fiscal year before current fiscal year	560	211
Year three, originated, two years before current fiscal year	189	132
Year four, originated, three years before current fiscal year	112	78
Year five, originated, four years before current fiscal year	68	28
Originated, more than five years before current fiscal year	44	34
Revolving loans	13,877	12,327
Revolving loans converted to term	0	0
Total finance receivables and loans	15,121	13,450
Automotive | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	2	23
Year two, originated, fiscal year before current fiscal year	19	47
Year three, originated, two years before current fiscal year	45	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	24	21
Revolving loans	1,016	1,016
Revolving loans converted to term	0	0
Total finance receivables and loans	1,106	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	49	27
Revolving loans converted to term	0	0
Total finance receivables and loans	50	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	0
Revolving loans	16
Revolving loans converted to term	0
Total finance receivables and loans	16
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	185	771
Year two, originated, fiscal year before current fiscal year	786	627
Year three, originated, two years before current fiscal year	575	786
Year four, originated, three years before current fiscal year	504	629
Year five, originated, four years before current fiscal year	445	101
Originated, more than five years before current fiscal year	506	425
Revolving loans	5,937	5,678
Revolving loans converted to term	186	137
Total finance receivables and loans	9,124	9,154
Financing receivable, year five, originated, four years before current fiscal year, charge-off	56
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	185	594
Year two, originated, fiscal year before current fiscal year	553	469
Year three, originated, two years before current fiscal year	377	607
Year four, originated, three years before current fiscal year	306	419
Year five, originated, four years before current fiscal year	360	54
Originated, more than five years before current fiscal year	206	133
Revolving loans	5,611	5,344
Revolving loans converted to term	147	89
Total finance receivables and loans	7,745	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	233	158
Year three, originated, two years before current fiscal year	175	175
Year four, originated, three years before current fiscal year	195	95
Year five, originated, four years before current fiscal year	51	47
Originated, more than five years before current fiscal year	154	128
Revolving loans	281	278
Revolving loans converted to term	24	35
Total finance receivables and loans	1,113	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	23	4
Year four, originated, three years before current fiscal year	3	51
Year five, originated, four years before current fiscal year	27	0
Originated, more than five years before current fiscal year	120	139
Revolving loans	42	55
Revolving loans converted to term	15	13
Total finance receivables and loans	230	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	3	0
Revolving loans converted to term	0	0
Total finance receivables and loans	29	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	7	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	7	1
Commercial real estate | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	385	1,481
Year two, originated, fiscal year before current fiscal year	1,538	1,150
Year three, originated, two years before current fiscal year	1,192	953
Year four, originated, three years before current fiscal year	931	698
Year five, originated, four years before current fiscal year	680	369
Originated, more than five years before current fiscal year	896	716
Revolving loans	9	9
Revolving loans converted to term	31	13
Total finance receivables and loans	5,662	5,389
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	385	1,481
Year two, originated, fiscal year before current fiscal year	1,529	1,118
Year three, originated, two years before current fiscal year	1,161	951
Year four, originated, three years before current fiscal year	929	679
Year five, originated, four years before current fiscal year	662	369
Originated, more than five years before current fiscal year	895	716
Revolving loans	9	9
Revolving loans converted to term	31	13
Total finance receivables and loans	5,601	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	7	32
Year three, originated, two years before current fiscal year	31	2
Year four, originated, three years before current fiscal year	2	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	58	$ 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	2
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	$ 3