Leasing (Depreciation Expense on Operating Lease Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating lease revenue	$ 385	$ 397	$ 1,179	$ 1,196
Depreciation expense on operating lease assets (excluding remarketing gains)	269	277	812	813
Remarketing gains, net	(57)	(39)	(174)	(139)
Net depreciation expense on operating lease assets	212	238	638	674
Variable lease payments, excessive wear and tear	$ 3	$ 2	$ 7	$ 5