Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators Consumer) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 139,439	$ 135,748
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	104,977	106,610
Consumer | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year		40,946
Year two, originated, fiscal year before current fiscal year		34,750
Year three, originated, two years before current fiscal year		12,893
Year four, originated, three years before current fiscal year		7,698
Year five, originated, four years before current fiscal year		4,071
Originated, more than five years before current fiscal year		4,994
Revolving loans		1,794
Revolving loans converted to term		21
Total finance receivables and loans		107,167
Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	31,450	37,114
Year two, originated, fiscal year before current fiscal year	25,350	23,415
Year three, originated, two years before current fiscal year	15,373	10,893
Year four, originated, three years before current fiscal year	6,555	6,872
Year five, originated, four years before current fiscal year	3,587	3,480
Originated, more than five years before current fiscal year	2,071	2,072
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	84,386	83,846
Liability excluded from amortized cost of hedged asset, portfolio layer method	66	560
Consumer | Consumer mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	153	2,309
Year two, originated, fiscal year before current fiscal year	2,181	10,927
Year three, originated, two years before current fiscal year	10,396	1,950
Year four, originated, three years before current fiscal year	1,843	821
Year five, originated, four years before current fiscal year	752	590
Originated, more than five years before current fiscal year	3,178	2,922
Revolving loans	145	195
Revolving loans converted to term	19	21
Total finance receivables and loans	18,667	19,735
Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	153	2,309
Year two, originated, fiscal year before current fiscal year	2,181	10,927
Year three, originated, two years before current fiscal year	10,396	1,950
Year four, originated, three years before current fiscal year	1,843	821
Year five, originated, four years before current fiscal year	752	590
Originated, more than five years before current fiscal year	3,117	2,848
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	18,442	19,445
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	61	74
Revolving loans	145	195
Revolving loans converted to term	19	21
Total finance receivables and loans	225	290
Consumer | Other
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	1,990
Revolving loans converted to term	0
Total finance receivables and loans	1,990	3,589
Fair value, option, carrying amount, financing receivable, no allowance		3	$ 7
Consumer | Other | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year		1,523
Year two, originated, fiscal year before current fiscal year		408
Year three, originated, two years before current fiscal year		50
Year four, originated, three years before current fiscal year		5
Year five, originated, four years before current fiscal year		1
Originated, more than five years before current fiscal year		0
Revolving loans		1,599
Revolving loans converted to term		0
Total finance receivables and loans		3,586
Consumer | Personal Lending
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	0	1,990
Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year		1,523
Year two, originated, fiscal year before current fiscal year		408
Year three, originated, two years before current fiscal year		50
Year four, originated, three years before current fiscal year		5
Year five, originated, four years before current fiscal year		1
Originated, more than five years before current fiscal year		0
Revolving loans		0
Revolving loans converted to term		0
Total finance receivables and loans		1,987
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	1,990	1,599
Revolving loans converted to term	0	0
Total finance receivables and loans	1,990	1,599
Consumer Portfolio Segment, Excludes Basis Adjustment for Automotive Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	31,603
Year two, originated, fiscal year before current fiscal year	27,531
Year three, originated, two years before current fiscal year	25,769
Year four, originated, three years before current fiscal year	8,398
Year five, originated, four years before current fiscal year	4,339
Originated, more than five years before current fiscal year	5,249
Revolving loans	2,135
Revolving loans converted to term	19
Total finance receivables and loans	105,043
Current | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	30,677	36,127
Year two, originated, fiscal year before current fiscal year	23,699	22,102
Year three, originated, two years before current fiscal year	14,209	10,341
Year four, originated, three years before current fiscal year	6,132	6,451
Year five, originated, four years before current fiscal year	3,306	3,237
Originated, more than five years before current fiscal year	1,876	1,890
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	79,899	80,148
Current | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	152	2,292
Year two, originated, fiscal year before current fiscal year	2,170	10,893
Year three, originated, two years before current fiscal year	10,374	1,946
Year four, originated, three years before current fiscal year	1,836	815
Year five, originated, four years before current fiscal year	747	577
Originated, more than five years before current fiscal year	3,073	2,805
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	18,352	19,328
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	51	62
Revolving loans	142	191
Revolving loans converted to term	17	18
Total finance receivables and loans	210	271
Current | Consumer | Personal Lending | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year		1,492
Year two, originated, fiscal year before current fiscal year		392
Year three, originated, two years before current fiscal year		48
Year four, originated, three years before current fiscal year		5
Year five, originated, four years before current fiscal year		1
Originated, more than five years before current fiscal year		0
Revolving loans		0
Revolving loans converted to term		0
Total finance receivables and loans		1,938
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	1,828	1,518
Revolving loans converted to term	0	0
Total finance receivables and loans	1,828	1,518
30–59 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	539	707
Year two, originated, fiscal year before current fiscal year	1,041	878
Year three, originated, two years before current fiscal year	739	370
Year four, originated, three years before current fiscal year	270	284
Year five, originated, four years before current fiscal year	181	165
Originated, more than five years before current fiscal year	122	120
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	2,892	2,524
30–59 days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1	15
Year two, originated, fiscal year before current fiscal year	8	29
Year three, originated, two years before current fiscal year	14	4
Year four, originated, three years before current fiscal year	3	3
Year five, originated, four years before current fiscal year	3	4
Originated, more than five years before current fiscal year	20	26
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	49	81
30–59 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	3	4
Revolving loans	0	1
Revolving loans converted to term	1	0
Total finance receivables and loans	4	5
30–59 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		14
Year two, originated, fiscal year before current fiscal year		6
Year three, originated, two years before current fiscal year		1
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		0
Revolving loans converted to term		0
Total finance receivables and loans		21
30–59 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	39	22
Revolving loans converted to term	0	0
Total finance receivables and loans	39	22
60–89 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	170	207
Year two, originated, fiscal year before current fiscal year	443	324
Year three, originated, two years before current fiscal year	303	135
Year four, originated, three years before current fiscal year	109	99
Year five, originated, four years before current fiscal year	68	55
Originated, more than five years before current fiscal year	45	38
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	1,138	858
60–89 days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	2
Year two, originated, fiscal year before current fiscal year	2	4
Year three, originated, two years before current fiscal year	4	0
Year four, originated, three years before current fiscal year	3	1
Year five, originated, four years before current fiscal year	0	1
Originated, more than five years before current fiscal year	5	3
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	14	11
60–89 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	0
Revolving loans	1	0
Revolving loans converted to term	0	1
Total finance receivables and loans	2	1
60–89 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		9
Year two, originated, fiscal year before current fiscal year		5
Year three, originated, two years before current fiscal year		1
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		0
Revolving loans converted to term		0
Total finance receivables and loans		15
60–89 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	34	18
Revolving loans converted to term	0	0
Total finance receivables and loans	34	18
90 or more days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	64	73
Year two, originated, fiscal year before current fiscal year	167	111
Year three, originated, two years before current fiscal year	122	47
Year four, originated, three years before current fiscal year	44	38
Year five, originated, four years before current fiscal year	32	23
Originated, more than five years before current fiscal year	28	24
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	457	316
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	1	1
Year three, originated, two years before current fiscal year	4	0
Year four, originated, three years before current fiscal year	1	2
Year five, originated, four years before current fiscal year	2	8
Originated, more than five years before current fiscal year	19	14
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	27	25
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	6	8
Revolving loans	2	3
Revolving loans converted to term	1	2
Total finance receivables and loans	9	13
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		8
Year two, originated, fiscal year before current fiscal year		5
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		0
Revolving loans converted to term		0
Total finance receivables and loans		13
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	89	41
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 89	$ 41