Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Financing revenue and other interest income
Net depreciation expense on operating lease assets	$ 220	$ 169	$ 155	$ 192	$ 213	$ 206	$ 196	$ 225					$ 736		$ 840		$ 914
Income tax (benefit) expense from continuing operations	0	67	60	40	10	(51)	96	89					167		144		627
Net income	$ 108	$ 198	$ 219	$ 143	$ 62	$ 285	$ 311	$ 299	$ 362	$ 610	$ 560	$ 895	$ 668		$ 957		$ 1,714
Basic earnings per common share
Net income (in dollars per share)	$ 0.26	$ 0.55	$ 0.63	$ 0.38	$ 0.11	$ 0.85	$ 0.93	$ 0.90					$ 1.82	[1]	$ 2.79	[1]	$ 5.06	[1]
Diluted earnings per common share
Net income (in dollars per share)	$ 0.26	$ 0.55	$ 0.62	$ 0.37	$ 0.11	$ 0.84	$ 0.93	$ 0.89					$ 1.80	[1]	$ 2.77	[1]	$ 5.03	[1]
Comprehensive (loss) income	$ (423)	$ 814	$ 199	$ (30)	$ 1,011	$ (617)	$ 224	$ 582					$ 560		$ 1,200		$ (2,187)
Investment in operating leases, net	7,991	7,967	8,126	8,582	9,085	9,509	9,890	10,218	8,126	9,890	7,967	9,509	7,991		9,085
Other assets	10,660	9,947	9,949	9,420	9,418	9,612	9,155	9,142	9,949	9,155	9,947	9,612	10,660		9,418
Retained earnings	270	284	208	111	91	148	(15)	(205)	208	(15)	284	148	270		91
Operating activities
Net income	$ 108	198	219	143	62	285	311	299	362	610	560	895	668		957		1,714
Reconciliation of net income to net cash provided by operating activities
Depreciation and amortization				310				316	582	608	864	912	1,199		1,227		1,327
Net change in
Deferred income taxes				(50)				26	(117)	51	(218)	(73)	(436)		(81)		553
Net cash provided by operating activities				1,266				1,413	2,720	2,975	3,577	4,609	4,528		4,557		6,247
Investing activities
Disposals of operating lease assets				964				725	2,164	1,625	3,113	2,455	3,808		3,228		3,023
Net cash provided by (used in) investing activities				3,576				(363)	2,590	(2,435)	3,785	(4,144)	$ 4,991		(7,182)		$ (17,263)
As Originally Reported
Financing revenue and other interest income
Net depreciation expense on operating lease assets		201	177	204	222	212	200	226							860
Income tax (benefit) expense from continuing operations		(124)	(37)	14	(13)	(68)	74	68							61
Net income		$ 357	$ 294	$ 157	$ 76	$ 296	$ 329	$ 319	451	648	808	944			$ 1,020
Basic earnings per common share
Net income (in dollars per share)		$ 1.07	$ 0.87	$ 0.42	$ 0.16	$ 0.88	$ 0.99	$ 0.96							$ 3.00
Diluted earnings per common share
Net income (in dollars per share)		$ 1.06	$ 0.86	$ 0.42	$ 0.16	$ 0.88	$ 0.99	$ 0.96							$ 2.98
Comprehensive (loss) income		$ 973	$ 274	$ (16)	$ 1,025	$ (606)	$ 242	$ 602							$ 1,263
Investment in operating leases, net		8,318	8,374	8,731	9,171	9,569	9,930	10,236	8,374	9,930	8,318	9,569			9,171
Other assets		9,907	9,853	9,348	9,395	9,601	9,153	9,144	9,853	9,153	9,907	9,601			9,395
Retained earnings		595	360	188	154	197	23	(185)	360	23	595	197			154
Operating activities
Net income		$ 357	$ 294	157	$ 76	$ 296	$ 329	319	451	648	808	944			1,020
Reconciliation of net income to net cash provided by operating activities
Depreciation and amortization				322				317	616	613	930	923			1,247
Net change in
Deferred income taxes				(1)				24	(44)	53	(201)	(62)			(58)
Net cash provided by operating activities				1,341				1,432	2,916	3,020	3,908	4,680			4,663
Investing activities
Disposals of operating lease assets				889				706	1,968	1,580	2,782	2,384			3,122
Net cash provided by (used in) investing activities				$ 3,501				$ (382)	$ 2,394	$ (2,480)	$ 3,454	$ (4,215)			$ (7,288)

[1] Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.