Condensed Consolidated Statement of Cash Flows (unaudited) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Operating activities
Net income		$ 352	$ 219	$ 127	$ 362
Reconciliation of net income to net cash provided by operating activities
Depreciation and amortization				690	582
Goodwill impairment		0	0	305	0	$ 118
Provision for credit losses		384	457	575	964
Loss (gain) on mortgage and automotive loans, net		4	(6)	3	(12)
Other loss (gain) on investments, net		(61)	7	438	(22)
Originations and purchases of loans held-for-sale				(912)	(1,074)
Proceeds from sales and repayments of loans held-for-sale				1,044	1,311
Net change in
Deferred income taxes				(249)	(117)
Interest payable				22	290
Other assets				(153)	184
Other liabilities				(115)	115
Other, net				112	137
Net cash provided by operating activities				1,887	2,720
Investing activities
Purchases of equity securities				(397)	(457)
Proceeds from sales of equity securities				376	459
Purchases of available-for-sale securities				(4,493)	(246)
Proceeds from sales of available-for-sale securities				4,157	63
Proceeds from repayments of available-for-sale securities				954	898
Purchases of held-to-maturity securities				(412)	0
Proceeds from repayments of held-to-maturity securities				238	229
Purchases of finance receivables and loans held-for-investment				(2,192)	(1,718)
Proceeds from sales of finance receivables and loans initially held-for-investment				5	1,067
Originations and repayments of finance receivables and loans initially held-for-investment and other, net				1,701	47
Purchases of operating lease assets				(1,900)	(1,609)
Disposals of operating lease assets				1,453	2,164
Proceeds from sale of operation or business unit, net				2,412	1,956
Net change in nonmarketable equity investments				(36)	77
Other, net				(298)	(340)
Net cash provided by investing activities				1,568	2,590
Financing activities
Net change in short-term borrowings				2,231	(175)
Net decrease in deposits				(3,626)	(2,545)
Proceeds from issuance of long-term debt				953	549
Repayments of long-term debt				(2,612)	(2,175)
Repurchases of common stock				(35)	(30)
Common stock dividends paid				(192)	(188)
Preferred stock dividends paid				(56)	(56)
Net cash used in financing activities				(3,337)	(4,620)
Effect of exchange-rate changes on cash and cash equivalents and restricted cash				10	(5)
Net increase in cash and cash equivalents and restricted cash				128	685
Cash and cash equivalents and restricted cash at beginning of year				11,380	7,439	7,439
Cash and cash equivalents and restricted cash at June 30,		11,508	8,124	11,508	8,124	11,380
Cash paid for
Interest				3,202	3,455
Income taxes				108	45
Noncash items
Held-to-maturity securities received in consideration for loans sold				0	56
Loans held-for-sale transferred to finance receivables and loans held-for-investment				19	18
Finance receivables and loans held-for-investment transferred to loans held-for-sale				2,391	1,390
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents on the Condensed Consolidated Balance Sheet		10,592	7,369	10,592	7,369	10,292
Restricted cash and cash equivalents and restricted cash held for securitization trusts included in other assets on the Condensed Consolidated Balance Sheet	[1]	916	755	916	755
Total cash and cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows		$ 11,508	$ 8,124	$ 11,508	$ 8,124	$ 11,380

[1] Refer to Note 11 for additional details describing the nature of restricted cash and cash equivalent balances.