Leases - Operating Leases as Lessee (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease cost	$ 356	$ 355	$ 359
Cash paid for amounts included in the measurement of operating lease liabilities	276	274	287
ROU assets arising from entering into new operating lease obligations	$ 253	$ 263	$ 343
Weighted average remaining lease term at December 31 (in years)	7 years	8 years	8 years
Weighted average discount rate at December 31	3.40%	2.90%	2.70%