Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Foreign Plan [Member]
Components of Net Periodic Benefit Cost:
Service cost	$ 12	$ 10	$ 9
Interest cost	22	23	21
Expected return on plan assets	(17)	(21)	(19)
Amortization of prior service cost	0	0	(1)
Amortization of net loss	3	2	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	0
Settlement loss recognized	4	0	0
Total pension cost	24	14	12
UNITED STATES
Components of Net Periodic Benefit Cost:
Service cost	15	13	13
Interest cost	40	41	42
Expected return on plan assets	(64)	(69)	(68)
Amortization of prior service cost	5	6	7
Amortization of net loss	18	18	18
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	1	4	4
Settlement loss recognized	0	0	0
Total pension cost	$ 15	$ 13	$ 16