Finance Receivables and Loans, Net - Schedule of Financing Receivable Credit Quality Indicators Consumer (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	$ 133,485	$ 136,030
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	100,831	103,285
Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	8,951	30,919
Year two, originated, fiscal year before current fiscal year	28,449	21,604
Year three, originated, two years before current fiscal year	19,461	16,607
Year four, originated, three years before current fiscal year	14,752	9,247
Year five, originated, four years before current fiscal year	7,989	3,344
Originated, more than five years before current fiscal year	4,278	2,077
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	83,880	83,798
Consumer | Consumer mortgage finance receivables
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	13
Year two, originated, fiscal year before current fiscal year	20	33
Year three, originated, two years before current fiscal year	32	1,914
Year four, originated, three years before current fiscal year	1,878	9,856
Year five, originated, four years before current fiscal year	9,726	1,721
Originated, more than five years before current fiscal year	5,181	3,564
Revolving loans	109	116
Revolving loans converted to term	17	17
Total finance receivables and loans	16,963	17,234
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		2,294
Revolving loans converted to term		0
Total finance receivables and loans	0	2,294
Consumer | Automotive
Financing Receivable, Credit Quality Indicator [Line Items]
Total finance receivables and loans	83,868	83,757
Liability excluded from amortized cost of hedged asset, portfolio layer method	12	41
Consumer Portfolio Segment, Excludes Basis Adjustment for Automotive Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	8,951	30,932
Year two, originated, fiscal year before current fiscal year	28,469	21,637
Year three, originated, two years before current fiscal year	19,493	18,521
Year four, originated, three years before current fiscal year	16,630	19,103
Year five, originated, four years before current fiscal year	17,715	5,065
Originated, more than five years before current fiscal year	9,459	5,641
Revolving loans	109	2,410
Revolving loans converted to term	17	17
Total finance receivables and loans	100,843	103,326
Current | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	8,935	30,322
Year two, originated, fiscal year before current fiscal year	27,767	20,387
Year three, originated, two years before current fiscal year	18,395	15,234
Year four, originated, three years before current fiscal year	13,598	8,368
Year five, originated, four years before current fiscal year	7,287	3,064
Originated, more than five years before current fiscal year	3,901	1,849
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	79,883	79,224
Current | Consumer | Consumer mortgage finance receivables
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	0	13
Year two, originated, fiscal year before current fiscal year	20	31
Year three, originated, two years before current fiscal year	31	1,901
Year four, originated, three years before current fiscal year	1,865	9,834
Year five, originated, four years before current fiscal year	9,702	1,714
Originated, more than five years before current fiscal year	5,125	3,503
Revolving loans	108	115
Revolving loans converted to term	15	15
Total finance receivables and loans	16,866	17,126
Current | 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		2,140
Revolving loans converted to term		0
Total finance receivables and loans		2,140
30–59 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	15	419
Year two, originated, fiscal year before current fiscal year	461	756
Year three, originated, two years before current fiscal year	659	841
Year four, originated, three years before current fiscal year	704	546
Year five, originated, four years before current fiscal year	437	174
Originated, more than five years before current fiscal year	232	141
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	2,508	2,877
30–59 days past due | Consumer | Consumer mortgage finance 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	7
Year four, originated, three years before current fiscal year	5	9
Year five, originated, four years before current fiscal year	5	5
Originated, more than five years before current fiscal year	20	27
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	30	48
30–59 days past due | 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		35
Revolving loans converted to term		0
Total finance receivables and loans		35
60–89 days past due | Consumer | Consumer automotive, excludes basis adjustment
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, originated, current fiscal year	1	131
Year two, originated, fiscal year before current fiscal year	160	338
Year three, originated, two years before current fiscal year	299	390
Year four, originated, three years before current fiscal year	330	240
Year five, originated, four years before current fiscal year	188	75
Originated, more than five years before current fiscal year	96	56
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	1,074	1,230
60–89 days past due | Consumer | Consumer mortgage finance 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	4
Year four, originated, three years before current fiscal year	3	4
Year five, originated, four years before current fiscal year	9	1
Originated, more than five years before current fiscal year	11	4
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	23	13
60–89 days past due | 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		33
Revolving loans converted to term		0
Total finance receivables and loans		33
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	0	47
Year two, originated, fiscal year before current fiscal year	61	123
Year three, originated, two years before current fiscal year	108	142
Year four, originated, three years before current fiscal year	120	93
Year five, originated, four years before current fiscal year	77	31
Originated, more than five years before current fiscal year	49	31
Revolving loans	0	0
Revolving loans converted to term	0	0
Total finance receivables and loans	415	467
90 or more days past due | Consumer | Consumer mortgage finance 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	2
Year three, originated, two years before current fiscal year	1	2
Year four, originated, three years before current fiscal year	5	9
Year five, originated, four years before current fiscal year	10	1
Originated, more than five years before current fiscal year	25	30
Revolving loans	1	1
Revolving loans converted to term	2	2
Total finance receivables and loans	$ 44	47
90 or more days past due | 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		86
Revolving loans converted to term		0
Total finance receivables and loans		$ 86