Description of Business, Basis of Presentation, and Significant Accounting Policies - Consolidated Statement of Income (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 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
Net income attributable to common shareholders	[1]													$ 558		$ 847		$ 1,604
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 income (loss)		$ (423)	$ 814	$ 199	$ (30)	$ 1,011	$ (617)	$ 224	$ 582					$ 560		$ 1,200		$ (2,187)
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 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
Net income attributable to common shareholders																$ 910
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 income (loss)			$ 973	$ 274	$ (16)	$ 1,025	$ (606)	$ 242	$ 602							$ 1,263
Adjustments
Financing revenue and other interest income
Net depreciation expense on operating lease assets																(20)
Income tax expense from continuing operations																83
Net income																(63)
Net income attributable to common shareholders																$ (63)
Basic earnings per common share
Net income (in dollars per share)																$ (0.21)
Diluted earnings per common share
Net income (in dollars per share)																$ (0.21)
Comprehensive income (loss)																$ (63)

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