Leases (Components of Lease Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Fixed operating lease expense	$ 246	$ 216	$ 196
Variable operating lease expense	59	46	45
Total operating lease expense	$ 305	$ 262	$ 241