Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 128,457	$ 122,268
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,207	2,419
Year two, originated, fiscal year before current fiscal year	2,306	1,896
Year three, originated, two years before current fiscal year	1,785	1,586
Year four, originated, three years before current fiscal year	1,289	783
Year five, originated, four years before current fiscal year	673	663
Originated, more than five years before current fiscal year	1,414	1,052
Revolving loans	15,961	15,512
Revolving loans converted to term	139	131
Total finance receivables and loans	24,774	24,042
Automotive loan | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	191	354
Year two, originated, fiscal year before current fiscal year	291	192
Year three, originated, two years before current fiscal year	152	119
Year four, originated, three years before current fiscal year	93	65
Year five, originated, four years before current fiscal year	54	54
Originated, more than five years before current fiscal year	85	74
Revolving loans	11,308	11,371
Revolving loans converted to term	0	0
Total finance receivables and loans	12,174	12,229
Automotive loan | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	191	347
Year two, originated, fiscal year before current fiscal year	291	190
Year three, originated, two years before current fiscal year	151	112
Year four, originated, three years before current fiscal year	88	49
Year five, originated, four years before current fiscal year	42	23
Originated, more than five years before current fiscal year	60	56
Revolving loans	10,771	10,741
Revolving loans converted to term	0	0
Total finance receivables and loans	11,594	11,518
Automotive loan | 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	4	15
Year five, originated, four years before current fiscal year	12	31
Originated, more than five years before current fiscal year	25	18
Revolving loans	464	589
Revolving loans converted to term	0	0
Total finance receivables and loans	505	668
Automotive loan | 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	1	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	73	41
Revolving loans converted to term	0	0
Total finance receivables and loans	75	43
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	410	754
Year two, originated, fiscal year before current fiscal year	640	639
Year three, originated, two years before current fiscal year	626	565
Year four, originated, three years before current fiscal year	450	107
Year five, originated, four years before current fiscal year	109	249
Originated, more than five years before current fiscal year	477	299
Revolving loans	4,644	4,138
Revolving loans converted to term	130	123
Total finance receivables and loans	7,486	6,874
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	410	739
Year two, originated, fiscal year before current fiscal year	603	448
Year three, originated, two years before current fiscal year	430	374
Year four, originated, three years before current fiscal year	268	86
Year five, originated, four years before current fiscal year	65	99
Originated, more than five years before current fiscal year	185	68
Revolving loans	4,338	4,032
Revolving loans converted to term	85	83
Total finance receivables and loans	6,384	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	37	169
Year three, originated, two years before current fiscal year	178	96
Year four, originated, three years before current fiscal year	66	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	243	93
Revolving loans converted to term	28	17
Total finance receivables and loans	676	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	18	95
Year four, originated, three years before current fiscal year	116	0
Year five, originated, four years before current fiscal year	0	140
Originated, more than five years before current fiscal year	156	83
Revolving loans	55	13
Revolving loans converted to term	15	23
Total finance receivables and loans	360	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	56	26
Revolving loans	8	0
Revolving loans converted to term	2	0
Total finance receivables and loans	66	26
Commercial real estate | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	606	1,311
Year two, originated, fiscal year before current fiscal year	1,375	1,065
Year three, originated, two years before current fiscal year	1,007	902
Year four, originated, three years before current fiscal year	746	611
Year five, originated, four years before current fiscal year	510	360
Originated, more than five years before current fiscal year	852	679
Revolving loans	9	3
Revolving loans converted to term	9	8
Total finance receivables and loans	5,114	4,939
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	606	1,298
Year two, originated, fiscal year before current fiscal year	1,299	1,060
Year three, originated, two years before current fiscal year	1,005	873
Year four, originated, three years before current fiscal year	720	604
Year five, originated, four years before current fiscal year	510	342
Originated, more than five years before current fiscal year	826	653
Revolving loans	9	3
Revolving loans converted to term	9	8
Total finance receivables and loans	4,984	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	76	5
Year three, originated, two years before current fiscal year	2	29
Year four, originated, three years before current fiscal year	26	7
Year five, originated, four years before current fiscal year	0	18
Originated, more than five years before current fiscal year	23	19
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	127	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	3	7
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 3	$ 7