Finance Receivables and Loans, Net - Schedule of Financing Receivable Credit Quality Indicators Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 138,783	$ 139,439
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	103,585	104,977
Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	16,621	31,450
Year two, originated, fiscal year before current fiscal year	26,122	25,350
Year three, originated, two years before current fiscal year	20,620	15,373
Year four, originated, three years before current fiscal year	12,047	6,555
Year five, originated, four years before current fiscal year	4,780	3,587
Originated, more than five years before current fiscal year	3,487	2,071
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	83,677	84,386
Liability excluded from amortized cost of hedged asset, portfolio layer method	149	66
Consumer | Consumer mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	19	153
Year two, originated, fiscal year before current fiscal year	68	2,181
Year three, originated, two years before current fiscal year	2,117	10,396
Year four, originated, three years before current fiscal year	10,117	1,843
Year five, originated, four years before current fiscal year	1,789	752
Originated, more than five years before current fiscal year	3,749	3,178
Revolving loans	131	145
Revolving loans converted to term	18	19
Total finance receivables and loans	18,008	18,667
Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	19	153
Year two, originated, fiscal year before current fiscal year	68	2,181
Year three, originated, two years before current fiscal year	2,117	10,396
Year four, originated, three years before current fiscal year	10,117	1,843
Year five, originated, four years before current fiscal year	1,789	752
Originated, more than five years before current fiscal year	3,693	3,117
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	17,803	18,442
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	56	61
Revolving loans	131	145
Revolving loans converted to term	18	19
Total finance receivables and loans	205	225
Consumer | Other
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	2,049	1,990
Revolving loans converted to term	0	0
Total finance receivables and loans	2,049	1,990
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	2,049	1,990
Revolving loans converted to term	0	0
Total finance receivables and loans	2,049	1,990
Consumer Portfolio Segment, Excludes Basis Adjustment for Automotive Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	16,640	31,603
Year two, originated, fiscal year before current fiscal year	26,190	27,531
Year three, originated, two years before current fiscal year	22,737	25,769
Year four, originated, three years before current fiscal year	22,164	8,398
Year five, originated, four years before current fiscal year	6,569	4,339
Originated, more than five years before current fiscal year	7,236	5,249
Revolving loans	2,180	2,135
Revolving loans converted to term	18	19
Total finance receivables and loans	103,734	105,043
Current | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	16,472	30,677
Year two, originated, fiscal year before current fiscal year	25,093	23,699
Year three, originated, two years before current fiscal year	19,143	14,209
Year four, originated, three years before current fiscal year	11,071	6,132
Year five, originated, four years before current fiscal year	4,441	3,306
Originated, more than five years before current fiscal year	3,169	1,876
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	79,389	79,899
Current | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	19	152
Year two, originated, fiscal year before current fiscal year	68	2,170
Year three, originated, two years before current fiscal year	2,105	10,374
Year four, originated, three years before current fiscal year	10,093	1,836
Year five, originated, four years before current fiscal year	1,787	747
Originated, more than five years before current fiscal year	3,647	3,073
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	17,719	18,352
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	48	51
Revolving loans	129	142
Revolving loans converted to term	16	17
Total finance receivables and loans	193	210
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	1,910	1,828
Revolving loans converted to term	0	0
Total finance receivables and loans	1,910	1,828
30–59 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	114	539
Year two, originated, fiscal year before current fiscal year	675	1,041
Year three, originated, two years before current fiscal year	907	739
Year four, originated, three years before current fiscal year	616	270
Year five, originated, four years before current fiscal year	213	181
Originated, more than five years before current fiscal year	202	122
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	2,727	2,892
30–59 days past due | Consumer | Mortgage Finance
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	1
Year two, originated, fiscal year before current fiscal year	0	8
Year three, originated, two years before current fiscal year	7	14
Year four, originated, three years before current fiscal year	15	3
Year five, originated, four years before current fiscal year	0	3
Originated, more than five years before current fiscal year	21	20
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	43	49
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	3
Revolving loans	1	0
Revolving loans converted to term	0	1
Total finance receivables and loans	4	4
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	33	39
Revolving loans converted to term	0	0
Total finance receivables and loans	33	39
60–89 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	28	170
Year two, originated, fiscal year before current fiscal year	259	443
Year three, originated, two years before current fiscal year	418	303
Year four, originated, three years before current fiscal year	262	109
Year five, originated, four years before current fiscal year	90	68
Originated, more than five years before current fiscal year	74	45
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	1,131	1,138
60–89 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	0	2
Year three, originated, two years before current fiscal year	4	4
Year four, originated, three years before current fiscal year	4	3
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	6	5
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	14	14
60–89 days past due | Consumer | Mortgage — Legacy
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		1
Revolving loans		1
Revolving loans converted to term		0
Total finance receivables and loans		2
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	29	34
Revolving loans converted to term	0	0
Total finance receivables and loans	29	34
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	7	64
Year two, originated, fiscal year before current fiscal year	95	167
Year three, originated, two years before current fiscal year	152	122
Year four, originated, three years before current fiscal year	98	44
Year five, originated, four years before current fiscal year	36	32
Originated, more than five years before current fiscal year	42	28
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	430	457
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	0	1
Year three, originated, two years before current fiscal year	1	4
Year four, originated, three years before current fiscal year	5	1
Year five, originated, four years before current fiscal year	2	2
Originated, more than five years before current fiscal year	19	19
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	27	27
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	5	6
Revolving loans	1	2
Revolving loans converted to term	2	1
Total finance receivables and loans	8	9
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	77	89
Revolving loans converted to term	0	0
Total finance receivables and loans	$ 77	$ 89