Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Commercial) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 122,268	$ 118,534
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	2,419	2,711
Year two, originated, fiscal year before current fiscal year	1,896	2,122
Year three, originated, two years before current fiscal year	1,586	1,399
Year four, originated, three years before current fiscal year	783	1,272
Year five, originated, four years before current fiscal year	663	977
Originated, more than five years before current fiscal year	1,052	902
Revolving loans	15,512	19,807
Revolving loans converted to term	131	142
Total finance receivables and loans	24,042	29,332
Automotive loan | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	354	920
Year two, originated, fiscal year before current fiscal year	192	245
Year three, originated, two years before current fiscal year	119	117
Year four, originated, three years before current fiscal year	65	143
Year five, originated, four years before current fiscal year	54	86
Originated, more than five years before current fiscal year	74	52
Revolving loans	11,371	17,519
Revolving loans converted to term	0	0
Total finance receivables and loans	12,229	19,082
Automotive loan | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	347	869
Year two, originated, fiscal year before current fiscal year	190	220
Year three, originated, two years before current fiscal year	112	58
Year four, originated, three years before current fiscal year	49	91
Year five, originated, four years before current fiscal year	23	76
Originated, more than five years before current fiscal year	56	34
Revolving loans	10,741	15,433
Revolving loans converted to term	0	0
Total finance receivables and loans	11,518	16,781
Automotive loan | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	7	48
Year two, originated, fiscal year before current fiscal year	1	23
Year three, originated, two years before current fiscal year	7	59
Year four, originated, three years before current fiscal year	15	52
Year five, originated, four years before current fiscal year	31	9
Originated, more than five years before current fiscal year	18	18
Revolving loans	589	2,013
Revolving loans converted to term	0	0
Total finance receivables and loans	668	2,222
Automotive loan | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	3
Year two, originated, fiscal year before current fiscal year	1	2
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	1	0
Year five, originated, four years before current fiscal year	0	1
Originated, more than five years before current fiscal year	0	0
Revolving loans	41	72
Revolving loans converted to term	0	0
Total finance receivables and loans	43	78
Automotive loan | 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		1
Revolving loans converted to term		0
Total finance receivables and loans		1
Other | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	754	645
Year two, originated, fiscal year before current fiscal year	639	817
Year three, originated, two years before current fiscal year	565	367
Year four, originated, three years before current fiscal year	107	514
Year five, originated, four years before current fiscal year	249	183
Originated, more than five years before current fiscal year	299	288
Revolving loans	4,138	2,288
Revolving loans converted to term	123	140
Total finance receivables and loans	6,874	5,242
Other | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	739	536
Year two, originated, fiscal year before current fiscal year	448	622
Year three, originated, two years before current fiscal year	374	244
Year four, originated, three years before current fiscal year	86	210
Year five, originated, four years before current fiscal year	99	81
Originated, more than five years before current fiscal year	68	69
Revolving loans	4,032	2,142
Revolving loans converted to term	83	76
Total finance receivables and loans	5,929	3,980
Other | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	15	76
Year two, originated, fiscal year before current fiscal year	169	169
Year three, originated, two years before current fiscal year	96	123
Year four, originated, three years before current fiscal year	21	190
Year five, originated, four years before current fiscal year	10	102
Originated, more than five years before current fiscal year	122	115
Revolving loans	93	123
Revolving loans converted to term	17	43
Total finance receivables and loans	543	941
Other | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	33
Year two, originated, fiscal year before current fiscal year	22	26
Year three, originated, two years before current fiscal year	95	0
Year four, originated, three years before current fiscal year	0	108
Year five, originated, four years before current fiscal year	140	0
Originated, more than five years before current fiscal year	83	77
Revolving loans	13	21
Revolving loans converted to term	23	20
Total finance receivables and loans	376	285
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	6
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	26	27
Revolving loans	0	2
Revolving loans converted to term	0	1
Total finance receivables and loans	26	36
Commercial real estate | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,311	1,146
Year two, originated, fiscal year before current fiscal year	1,065	1,060
Year three, originated, two years before current fiscal year	902	915
Year four, originated, three years before current fiscal year	611	615
Year five, originated, four years before current fiscal year	360	708
Originated, more than five years before current fiscal year	679	562
Revolving loans	3	0
Revolving loans converted to term	8	2
Total finance receivables and loans	4,939	5,008
Commercial real estate | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1,298	1,108
Year two, originated, fiscal year before current fiscal year	1,060	928
Year three, originated, two years before current fiscal year	873	799
Year four, originated, three years before current fiscal year	604	580
Year five, originated, four years before current fiscal year	342	651
Originated, more than five years before current fiscal year	653	512
Revolving loans	3	0
Revolving loans converted to term	8	2
Total finance receivables and loans	4,841	4,580
Commercial real estate | Special Mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	13	38
Year two, originated, fiscal year before current fiscal year	5	132
Year three, originated, two years before current fiscal year	29	116
Year four, originated, three years before current fiscal year	7	32
Year five, originated, four years before current fiscal year	18	49
Originated, more than five years before current fiscal year	19	43
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	91	410
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	3
Year five, originated, four years before current fiscal year	0	6
Originated, more than five years before current fiscal year	7	7
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 7	16
Commercial real estate | 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		2
Originated, more than five years before current fiscal year		0
Revolving loans		0
Revolving loans converted to term		0
Total finance receivables and loans		$ 2