Parent Company Condensed Financial Information (Condensed Statement of Cash Flows) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net cash provided by operating activities		$ 4,663	$ 6,247	$ 4,042
Investing activities
Proceeds from sales of finance receivables and loans initially held-for-investment		258	55	376
Originations and repayments of finance receivables and loans held-for-investment and other, net		(5,040)	(7,927)	2,896
Purchases of equity securities		(339)	(539)	(1,346)
Proceeds from sales of equity securities		356	846	1,508
Net change in nonmarketable equity investments		(73)	27	56
Other, net		(579)	(531)	(443)
Net cash used in investing activities		(7,288)	(17,263)	(11,098)
Financing activities
Net change in short-term borrowings		898	2,399	(2,136)
Proceeds from issuance of long-term debt		5,705	7,125	2,997
Repayments of long-term debt		(4,595)	(6,464)	(6,068)
Repurchases of common stock		(33)	(1,650)	(1,994)
Preferred stock issuance		0	0	2,324
Trust preferred securities redemption		0	0	(2,710)
Common stock dividends paid		(368)	(384)	(324)
Preferred stock dividends paid		(110)	(110)	(57)
Net cash provided by (used in) financing activities		3,839	11,575	(3,848)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net increase (decrease) in cash and cash equivalents and restricted cash		1,217	552	(10,904)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash at beginning of year		6,222	5,670	16,574
Cash and cash equivalents and restricted cash at December 31,		7,439	6,222	5,670
Restricted Cash [Abstract]
Cash and cash equivalents		6,945	5,571
Restricted cash	[1]	494	651
Parent company
Operating activities
Net cash provided by operating activities		879	1,733	3,753
Investing activities
Proceeds from sales of finance receivables and loans initially held-for-investment		1	64	378
Originations and repayments of finance receivables and loans held-for-investment and other, net		(37)	(7)	189
Net change in loans — intercompany		(290)	(65)	(10)
Purchases of equity securities		0	0	(8)
Proceeds from sales of equity securities		5	1	0
Capital contributions to subsidiaries		(8)	0	0
Returns of contributed capital		1	52	24
Net change in nonmarketable equity investments		(2)	8	29
Other, net		(10)	(27)	44
Net cash used in investing activities		(340)	26	646
Financing activities
Net change in short-term borrowings		0	0	(2,136)
Proceeds from issuance of long-term debt		2,410	1,655	765
Repayments of long-term debt		(2,087)	(1,088)	(777)
Net change in debt — intercompany		227	(496)	(336)
Repurchases of common stock		(33)	(1,650)	(1,994)
Preferred stock issuance		0	0	2,324
Trust preferred securities redemption		0	0	(2,710)
Common stock dividends paid		(368)	(384)	(324)
Preferred stock dividends paid		(110)	(110)	(57)
Net cash provided by (used in) financing activities		39	(2,073)	(5,245)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net increase (decrease) in cash and cash equivalents and restricted cash		578	(314)	(846)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash at beginning of year		3,366	3,680	4,526
Cash and cash equivalents and restricted cash at December 31,		3,944	3,366	$ 3,680
Restricted Cash [Abstract]
Cash and cash equivalents		3,911	3,333
Restricted cash		$ 33	$ 33

[1] Restricted cash balances relate primarily to our securitization arrangements. Refer to Note 13 for additional details describing the nature of restricted cash balances.