Finance Receivables - Delinquency (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Charge-offs
2024	$ 18
2023	119
2022	123
2021	80
2020	34
Prior	31
Total	405
Retail Finance Receivables
Financing Receivable, Past Due [Line Items]
2024	7,993		$ 30,253
2023	27,542		20,259
2022	18,308		12,670
2021	11,329		6,842
2020	5,938		2,000
Prior	2,120		707
Total	$ 73,230	$ 67,704	$ 72,729
Percent of portfolio	100.00%	100.00%	100.00%
Charge-offs
Total	$ 405	$ 322
Retail Finance Receivables \| Performing Financial Instruments \| 0 - 30 days
Financing Receivable, Past Due [Line Items]
2024	7,973		$ 29,816
2023	27,054		19,602
2022	17,743		12,098
2021	10,856		6,533
2020	5,689		1,825
Prior	1,911		599
Total	$ 71,225	$ 66,109	$ 70,472
Percent of portfolio	97.30%	97.60%	96.90%
Retail Finance Receivables \| Nonperforming Financial Instruments \| 31 - 60 days
Financing Receivable, Past Due [Line Items]
2024	$ 19		$ 318
2023	342		470
2022	406		415
2021	352		227
2020	188		130
Prior	156		78
Total	$ 1,463	$ 1,188	$ 1,637
Percent of portfolio	2.00%	1.80%	2.30%
Retail Finance Receivables \| Nonperforming Financial Instruments \| Greater than 60 days
Financing Receivable, Past Due [Line Items]
2024	$ 1		$ 102
2023	125		168
2022	140		142
2021	109		76
2020	56		42
Prior	50		29
Total	$ 482	$ 363	$ 559
Percent of portfolio	0.70%	0.50%	0.80%
Retail Finance Receivables \| Nonperforming Financial Instruments \| Finance receivables more than 30 days delinquent
Financing Receivable, Past Due [Line Items]
2024	$ 20		$ 421
2023	467		637
2022	547		557
2021	461		302
2020	245		172
Prior	206		107
Total	$ 1,945	$ 1,551	$ 2,196
Percent of portfolio	2.70%	2.30%	3.00%
Retail Finance Receivables \| Nonperforming Financial Instruments \| In repossession
Financing Receivable, Past Due [Line Items]
2024	$ 0		$ 17
2023	21		20
2022	19		14
2021	12		6
2020	4		3
Prior	3		1
Total	$ 60	$ 44	$ 61
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]
2024	$ 20		$ 437
2023	488		657
2022	566		572
2021	473		308
2020	249		175
Prior	209		108
Total	$ 2,005	$ 1,595	$ 2,257
Percent of portfolio	2.70%	2.40%	3.10%

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