Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Foreign Plan [Member]
Components of Net Periodic Benefit Cost:
Service cost	$ 6	$ 8	$ 12
Interest cost	14	19	22
Expected return on plan assets	(7)	(14)	(17)
Amortization of prior service cost	0	0	0
Amortization of net loss	2	1	3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	0
Settlement loss recognized	0	0	4
Total pension cost	15	14	24
UNITED STATES
Components of Net Periodic Benefit Cost:
Service cost	12	11	15
Interest cost	35	44	40
Expected return on plan assets	(58)	(52)	(64)
Amortization of prior service cost	5	5	5
Amortization of net loss	14	15	18
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	1
Settlement loss recognized	0	0	0
Total pension cost	$ 8	$ 23	$ 15