Leases (Lease Cost and Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 81	$ 88	$ 161	$ 178
Short-term lease cost	2	1	3	2
Variable lease cost	26	30	63	64
Sublease income	(2)	(4)	(6)	(9)
Net lease cost	$ 107	$ 115	221	235
Operating cash outflows from operating leases			189	194
Right of use assets obtained in exchange for new operating lease liabilities			$ 121	$ 114
Real Estate Lease
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term – real estate	8 years 3 months 18 days	8 years 7 months 6 days	8 years 3 months 18 days	8 years 7 months 6 days
Weighted-average discount rate – real estate leases	3.21%	2.75%	3.21%	2.75%