Leases (Lease Cost and Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 80	$ 90
Short-term lease cost	1	1
Variable lease cost	37	34
Sublease income	(4)	(5)
Net lease cost	114	120
Operating cash outflows from operating leases	94	99
Right of use assets obtained in exchange for new operating lease liabilities	$ 76	$ 51
Real Estate Lease
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term – real estate	8 years 4 months 24 days	8 years 8 months 12 days
Weighted-average discount rate – real estate leases	3.12%	2.75%