Restructuring Restructuring Costs by Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 52	$ 129	$ 167	$ 65
Signal and Power Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring		67	125	39
Advanced Safety and User Experience
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 62	$ 42	$ 26