Segment Reporting (Narrative) (Details) - Operating Segments [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Long-lived assets	$ 8,069	$ 6,829	$ 6,220
Switzerland [Member]
Segment Reporting Information [Line Items]
Long-lived assets	900	900	900
Indonesia [Member]
Segment Reporting Information [Line Items]
Long-lived assets	800	800	700
Italy [Member]
Segment Reporting Information [Line Items]
Long-lived assets	$ 1,200	$ 700	$ 400