Benefit Plans (Net Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ (9)	$ (17)
Defined Benefit Plan, Benefit Obligation, Business Combination	0	(4)
Defined Benefit Plan, Plan Assets, Divestiture	(244)	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	1
CHANGE IN PROJECTED BENEFIT OBLIGATION:
Benefit obligation, beginning period	417	470
Service cost	8	12	$ 10
Interest cost	19	22	23
Defined Benefit Plan, Benefit Obligation, Interest cost	19	22
Plan amendments	0	0
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	0	(21)
Actuarial (gain) loss	37	(8)
Effect of foreign currency exchange rate changes	(4)	(38)
Benefit obligation, ending period	224	417	470
CHANGE IN PLAN ASSETS:
Fair value of plan assets, beginning period	410	455
Actual return on plan assets	19	6
Employer contributions	5	21
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	(21)
Effect of foreign currency exchange rate changes	0	(35)
Fair value of plan assets, ending period	129	410	455
Funded status as of December 31	(95)	(7)
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	1
Defined Benefit Plan, Plan Assets, Benefits Paid	(9)	(17)
Defined Benefit Plan, Plan Assets, Divestiture	(296)	0
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(65)	(105)
Defined Benefit Plan, Benefit Obligation, Business Combination	0	0
Defined Benefit Plan, Plan Assets, Divestiture	0	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	0
CHANGE IN PROJECTED BENEFIT OBLIGATION:
Benefit obligation, beginning period	1,118	1,257
Service cost	11	15	13
Interest cost	44	40	41
Plan amendments	0	10
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	0	0
Actuarial (gain) loss	134	(99)
Effect of foreign currency exchange rate changes	0	0
Benefit obligation, ending period	1,242	1,118	1,257
CHANGE IN PLAN ASSETS:
Fair value of plan assets, beginning period	1,026	1,127
Actual return on plan assets	185	(35)
Employer contributions	8	39
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	0
Effect of foreign currency exchange rate changes	0	0
Fair value of plan assets, ending period	1,154	1,026	$ 1,127
Funded status as of December 31	(88)	(92)
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Benefits Paid	(65)	(105)
Defined Benefit Plan, Plan Assets, Divestiture	$ 0	$ 0