Leases (Lease Cost and Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 88	$ 95	$ 178	$ 189
Short-term lease cost	1	2	2	3
Variable lease cost	30	26	64	63
Sublease income	(4)	(5)	(9)	(13)
Net lease cost	$ 115	$ 118	235	242
Operating cash outflows from operating leases			194	204
Right of use assets obtained in exchange for new operating lease liabilities			$ 114	$ 251
Real Estate Lease
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term	8 years 7 months 6 days	9 years 1 month 6 days	8 years 7 months 6 days	9 years 1 month 6 days
Weighted-average discount rate, percent	2.75%	2.76%	2.75%	2.76%