Business Segments - Equity In Net Income of Investees Accounted For By Equity Method (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 01, 2015
Segment Reporting Information [Line Items]
Equity in income	$ 0	$ 0	$ 0
DGT | Asia Pacific
Segment Reporting Information [Line Items]
Equity interest prior to dissolution				25.00%
NGY | Asia Pacific
Segment Reporting Information [Line Items]
Equity interest prior to dissolution				25.00%
Operating Segments
Segment Reporting Information [Line Items]
Equity in income	(5)	(1)	(16)
Operating Segments | Americas
Segment Reporting Information [Line Items]
Equity in income	(5)	0	(3)
Operating Segments | Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Equity in income	0	(1)	(1)
Operating Segments | Asia Pacific
Segment Reporting Information [Line Items]
Equity in income	$ 0	$ 0	$ (12)