Finance Receivables - Schedule of Delinquency (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Gross charge-offs
2025	$ 0		$ 171
2024	133		556
2023	147		495
2022	101		305
2021	61		126
Prior	37		102
Total	479		1,754
Retail Finance Receivables
Financing Receivable, Past Due [Line Items]
2025	9,141		31,101
2024	28,510		20,100
2023	18,006		12,802
2022	11,240		7,642
2021	6,586		3,575
Prior	3,511		847
Total	$ 76,995	$ 73,230	$ 76,066
Percent of portfolio	100.00%	100.00%	100.00%
Gross charge-offs
Total	$ 479	$ 405
Retail Finance Receivables \| Performing Financial Instruments \| 0 - 30 days
Financing Receivable, Past Due [Line Items]
2025	9,115		$ 30,581
2024	27,942		19,411
2023	17,420		12,207
2022	10,750		7,178
2021	6,228		3,350
Prior	3,253		710
Total	$ 74,707	$ 71,225	$ 73,438
Percent of portfolio	97.00%	97.30%	96.50%
Retail Finance Receivables \| Nonperforming Financial Instruments \| 31 - 60 days
Financing Receivable, Past Due [Line Items]
2025	$ 25		$ 374
2024	404		481
2023	419		425
2022	357		340
2021	269		166
Prior	193		99
Total	$ 1,667	$ 1,463	$ 1,885
Percent of portfolio	2.20%	2.00%	2.50%
Retail Finance Receivables \| Nonperforming Financial Instruments \| Greater than 60 days
Financing Receivable, Past Due [Line Items]
2025	$ 1		$ 128
2024	143		188
2023	146		155
2022	121		115
2021	83		55
Prior	62		36
Total	$ 556	$ 482	$ 677
Percent of portfolio	0.70%	0.70%	0.90%
Retail Finance Receivables \| Nonperforming Financial Instruments \| Finance receivables more than 30 days delinquent
Financing Receivable, Past Due [Line Items]
2025	$ 26		$ 502
2024	547		669
2023	566		580
2022	478		455
2021	351		221
Prior	255		135
Total	$ 2,223	$ 1,945	$ 2,562
Percent of portfolio	2.90%	2.70%	3.40%
Retail Finance Receivables \| Nonperforming Financial Instruments \| In repossession
Financing Receivable, Past Due [Line Items]
2025	$ 0		$ 17
2024	21		19
2023	20		14
2022	13		10
2021	7		3
Prior	3		2
Total	$ 65	$ 60	$ 66
Percent of portfolio	0.10%	0.10%	0.10%
Retail Finance Receivables \| Nonperforming Financial Instruments \| Finance receivables more than 30 days delinquent or in repossession
Financing Receivable, Past Due [Line Items]
2025	$ 27		$ 519
2024	568		689
2023	585		595
2022	491		464
2021	359		225
Prior	259		136
Total	$ 2,288	$ 2,005	$ 2,628
Percent of portfolio	3.00%	2.70%	3.50%

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