Postretirement Benefits (Narrative) (Details) - Other Postretirement Benefits Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recognized in other comprehensive income	$ 4
Total recognized in net periodic benefit cost or OCI	5	$ 3	$ (25)
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recognized in other comprehensive income	(41)
Total recognized in net periodic benefit cost or OCI	$ (25)	$ 25	$ 42