Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 132,456	$ 122,268
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,986	2,419
Year two, originated, fiscal year before current fiscal year	2,188	1,896
Year three, originated, two years before current fiscal year	1,734	1,586
Year four, originated, three years before current fiscal year	1,228	783
Year five, originated, four years before current fiscal year	574	663
Originated, more than five years before current fiscal year	1,262	1,052
Revolving loans	16,619	15,512
Revolving loans converted to term	145	131
Total finance receivables and loans	25,736	24,042
Consumer automotive | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	405	354
Year two, originated, fiscal year before current fiscal year	277	192
Year three, originated, two years before current fiscal year	142	119
Year four, originated, three years before current fiscal year	89	65
Year five, originated, four years before current fiscal year	43	54
Originated, more than five years before current fiscal year	63	74
Revolving loans	11,139	11,371
Revolving loans converted to term	0	0
Total finance receivables and loans	12,158	12,229
Consumer automotive | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	405	347
Year two, originated, fiscal year before current fiscal year	277	190
Year three, originated, two years before current fiscal year	142	112
Year four, originated, three years before current fiscal year	85	49
Year five, originated, four years before current fiscal year	32	23
Originated, more than five years before current fiscal year	40	56
Revolving loans	10,568	10,741
Revolving loans converted to term	0	0
Total finance receivables and loans	11,549	11,518
Consumer automotive | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	7
Year two, originated, fiscal year before current fiscal year	0	1
Year three, originated, two years before current fiscal year	0	7
Year four, originated, three years before current fiscal year	3	15
Year five, originated, four years before current fiscal year	11	31
Originated, more than five years before current fiscal year	23	18
Revolving loans	536	589
Revolving loans converted to term	0	0
Total finance receivables and loans	573	668
Consumer 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	1
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	1	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	35	41
Revolving loans converted to term	0	0
Total finance receivables and loans	36	43
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	632	754
Year two, originated, fiscal year before current fiscal year	638	639
Year three, originated, two years before current fiscal year	608	565
Year four, originated, three years before current fiscal year	415	107
Year five, originated, four years before current fiscal year	99	249
Originated, more than five years before current fiscal year	428	299
Revolving loans	5,471	4,138
Revolving loans converted to term	134	123
Total finance receivables and loans	8,425	6,874
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	632	739
Year two, originated, fiscal year before current fiscal year	586	448
Year three, originated, two years before current fiscal year	428	374
Year four, originated, three years before current fiscal year	191	86
Year five, originated, four years before current fiscal year	55	99
Originated, more than five years before current fiscal year	182	68
Revolving loans	5,152	4,032
Revolving loans converted to term	92	83
Total finance receivables and loans	7,318	5,929
Other | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	15
Year two, originated, fiscal year before current fiscal year	52	169
Year three, originated, two years before current fiscal year	176	96
Year four, originated, three years before current fiscal year	109	21
Year five, originated, four years before current fiscal year	44	10
Originated, more than five years before current fiscal year	80	122
Revolving loans	261	93
Revolving loans converted to term	29	17
Total finance receivables and loans	751	543
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	22
Year three, originated, two years before current fiscal year	4	95
Year four, originated, three years before current fiscal year	115	0
Year five, originated, four years before current fiscal year	0	140
Originated, more than five years before current fiscal year	140	83
Revolving loans	57	13
Revolving loans converted to term	13	23
Total finance receivables and loans	329	376
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	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	26	26
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	26	26
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	949	1,311
Year two, originated, fiscal year before current fiscal year	1,273	1,065
Year three, originated, two years before current fiscal year	984	902
Year four, originated, three years before current fiscal year	724	611
Year five, originated, four years before current fiscal year	432	360
Originated, more than five years before current fiscal year	771	679
Revolving loans	9	3
Revolving loans converted to term	11	8
Total finance receivables and loans	5,153	4,939
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	949	1,298
Year two, originated, fiscal year before current fiscal year	1,196	1,060
Year three, originated, two years before current fiscal year	982	873
Year four, originated, three years before current fiscal year	705	604
Year five, originated, four years before current fiscal year	432	342
Originated, more than five years before current fiscal year	769	653
Revolving loans	9	3
Revolving loans converted to term	11	8
Total finance receivables and loans	5,053	4,841
Commercial real estate | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	13
Year two, originated, fiscal year before current fiscal year	77	5
Year three, originated, two years before current fiscal year	2	29
Year four, originated, three years before current fiscal year	19	7
Year five, originated, four years before current fiscal year	0	18
Originated, more than five years before current fiscal year	1	19
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	99	91
Commercial real estate | 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	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	1	7
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 1	$ 7