Employee Benefits (Narrative Defined Contribution Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Defined Contribution Plan [Line Items]
Maximum employee contribution as a percentage of annual compensation	100.00%
Employer contributions to plans	$ 20	$ 21	$ 23
Foreign Plan [Member]
Defined Contribution Plan [Line Items]
Employer Contributions to Plan	4	5	5
Defined Contribution Retirement Plan [Member] | United States [Member]
Defined Contribution Plan [Line Items]
Employer Contributions to Plan	$ 32	$ 31	$ 29