Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Consumer) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 125,365	$ 122,268
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	99,869	98,226
Consumer | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	11,413	46,869
Year two, originated, fiscal year before current fiscal year	43,625	20,088
Year three, originated, two years before current fiscal year	17,822	13,015
Year four, originated, three years before current fiscal year	11,371	7,800
Year five, originated, four years before current fiscal year	6,625	4,661
Originated, more than five years before current fiscal year	7,719	4,562
Revolving loans	1,264	1,197
Revolving loans converted to term	23	27
Total finance receivables and loans	99,862	98,219
Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	10,138	35,802
Year two, originated, fiscal year before current fiscal year	32,285	17,736
Year three, originated, two years before current fiscal year	15,632	12,010
Year four, originated, three years before current fiscal year	10,451	7,028
Year five, originated, four years before current fiscal year	5,948	3,610
Originated, more than five years before current fiscal year	4,457	2,066
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	78,911	78,252
Consumer | Mortgage/Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	898	10,227
Year two, originated, fiscal year before current fiscal year	10,641	2,215
Year three, originated, two years before current fiscal year	2,083	986
Year four, originated, three years before current fiscal year	905	767
Year five, originated, four years before current fiscal year	674	1,050
Originated, more than five years before current fiscal year	3,261	2,496
Revolving loans	228	244
Revolving loans converted to term	23	27
Total finance receivables and loans	18,713	18,012
Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	898	10,227
Year two, originated, fiscal year before current fiscal year	10,641	2,215
Year three, originated, two years before current fiscal year	2,083	986
Year four, originated, three years before current fiscal year	905	767
Year five, originated, four years before current fiscal year	674	1,050
Originated, more than five years before current fiscal year	3,171	2,399
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	18,372	17,644
Consumer | Mortgage - Legacy
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	90	97
Revolving loans	228	244
Revolving loans converted to term	23	27
Total finance receivables and loans	341	368
Consumer | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	2,245	1,962
Finance receivables, fair value	7	7	$ 8	$ 8
Consumer | Other | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	377	840
Year two, originated, fiscal year before current fiscal year	699	137
Year three, originated, two years before current fiscal year	107	19
Year four, originated, three years before current fiscal year	15	5
Year five, originated, four years before current fiscal year	3	1
Originated, more than five years before current fiscal year	1	0
Revolving loans	1,036	953
Revolving loans converted to term	0	0
Total finance receivables and loans	2,238	1,955
Consumer | Personal Lending
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	1,209	1,009
Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	377	840
Year two, originated, fiscal year before current fiscal year	699	137
Year three, originated, two years before current fiscal year	107	19
Year four, originated, three years before current fiscal year	15	5
Year five, originated, four years before current fiscal year	3	1
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	1,202	1,002
Consumer | Credit card receivables
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	0	0
Revolving loans	1,036	953
Revolving loans converted to term	0	0
Total finance receivables and loans	1,036	953
Current | Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	10,120	35,222
Year two, originated, fiscal year before current fiscal year	31,561	17,218
Year three, originated, two years before current fiscal year	15,171	11,512
Year four, originated, three years before current fiscal year	10,051	6,692
Year five, originated, four years before current fiscal year	5,678	3,403
Originated, more than five years before current fiscal year	4,186	1,911
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	76,767	75,958
Current | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	895	10,169
Year two, originated, fiscal year before current fiscal year	10,614	2,212
Year three, originated, two years before current fiscal year	2,079	977
Year four, originated, three years before current fiscal year	895	744
Year five, originated, four years before current fiscal year	655	1,041
Originated, more than five years before current fiscal year	3,132	2,363
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	18,270	17,506
Current | Consumer | Mortgage - Legacy
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	75	79
Revolving loans	221	238
Revolving loans converted to term	20	23
Total finance receivables and loans	316	340
Current | Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	375	821
Year two, originated, fiscal year before current fiscal year	681	133
Year three, originated, two years before current fiscal year	104	18
Year four, originated, three years before current fiscal year	15	5
Year five, originated, four years before current fiscal year	3	1
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	1,179	978
Current | Consumer | Credit card receivables
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	0	0
Revolving loans	1,008	932
Revolving loans converted to term	0	0
Total finance receivables and loans	1,008	932
Financing receivables, 30 to 59 days past due | Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	17	424
Year two, originated, fiscal year before current fiscal year	512	353
Year three, originated, two years before current fiscal year	314	334
Year four, originated, three years before current fiscal year	272	226
Year five, originated, four years before current fiscal year	184	139
Originated, more than five years before current fiscal year	179	101
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	1,478	1,577
Financing receivables, 30 to 59 days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	3	50
Year two, originated, fiscal year before current fiscal year	23	3
Year three, originated, two years before current fiscal year	3	3
Year four, originated, three years before current fiscal year	4	7
Year five, originated, four years before current fiscal year	6	2
Originated, more than five years before current fiscal year	15	12
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	54	77
Financing receivables, 30 to 59 days past due | Consumer | Mortgage - Legacy
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	2	2
Revolving loans	1	1
Revolving loans converted to term	1	0
Total finance receivables and loans	4	3
Financing receivables, 30 to 59 days past due | Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	2	9
Year two, originated, fiscal year before current fiscal year	7	2
Year three, originated, two years before current fiscal year	1	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	0	0
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	10	11
Financing receivables, 30 to 59 days past due | Consumer | Credit card receivables
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	0	0
Revolving loans	8	6
Revolving loans converted to term	0	0
Total finance receivables and loans	8	6
Financing receivables, 60 to 89 days past due | Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1	115
Year two, originated, fiscal year before current fiscal year	153	114
Year three, originated, two years before current fiscal year	105	108
Year four, originated, three years before current fiscal year	86	70
Year five, originated, four years before current fiscal year	55	41
Originated, more than five years before current fiscal year	52	28
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	452	476
Financing receivables, 60 to 89 days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	8
Year two, originated, fiscal year before current fiscal year	1	0
Year three, originated, two years before current fiscal year	1	1
Year four, originated, three years before current fiscal year	1	0
Year five, originated, four years before current fiscal year	2	0
Originated, more than five years before current fiscal year	2	5
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	7	14
Financing receivables, 60 to 89 days past due | Consumer | Mortgage - Legacy
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	1
Revolving loans	0	0
Revolving loans converted to term	0	1
Total finance receivables and loans	1	2
Financing receivables, 60 to 89 days past due | Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	6
Year two, originated, fiscal year before current fiscal year	6	1
Year three, originated, two years before current fiscal year	1	1
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	0	0
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	7	8
Financing receivables, 60 to 89 days past due | Consumer | Credit card receivables
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	0	0
Revolving loans	6	5
Revolving loans converted to term	0	0
Total finance receivables and loans	6	5
Financing receivables, 90 or more days past due | Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	41
Year two, originated, fiscal year before current fiscal year	59	51
Year three, originated, two years before current fiscal year	42	56
Year four, originated, three years before current fiscal year	42	40
Year five, originated, four years before current fiscal year	31	27
Originated, more than five years before current fiscal year	40	26
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	214	241
Financing receivables, 90 or more days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	3	0
Year three, originated, two years before current fiscal year	0	5
Year four, originated, three years before current fiscal year	5	16
Year five, originated, four years before current fiscal year	11	7
Originated, more than five years before current fiscal year	22	19
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	41	47
Financing receivables, 90 or more days past due | Consumer | Mortgage - Legacy
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	12	15
Revolving loans	6	5
Revolving loans converted to term	2	3
Total finance receivables and loans	20	23
Financing receivables, 90 or more days past due | Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	4
Year two, originated, fiscal year before current fiscal year	5	1
Year three, originated, two years before current fiscal year	1	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	0	0
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	6	5
Financing receivables, 90 or more days past due | Consumer | Credit card receivables
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	0	0
Revolving loans	14	10
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 14	$ 10