Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Amortization of Intangible Assets	$ 47	$ 34	$ 37
Goodwill	1,059	1,059
Goodwill	3,792	$ 3,792
Long Lived Assets Held And Used [Member] | Nejapa [Member]
Goodwill [Line Items]
Impairment of Intangible Assets, Finite-lived	$ 23