Leases (Components of Lease Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finance lease cost:
Amortization of right-of-use assets	$ 96	$ 94	$ 86
Interest on lease liabilities	20	25	24
Operating lease cost	323	326	332
Short-term lease cost	71	62	75
Variable lease cost	18	12	14
Sublease income	(18)	(16)	(13)
Total lease costs, net	$ 510	$ 503	$ 518