Investments in Affiliates Technology Investments (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017
Cost Method Investments			$ 56	$ 6
Payments to Acquire Interest in Joint Venture			50	$ 3	$ 3
Advanced Safety and User Experience | Innoviz Technologies
Cost Method Investments			15
Payments to Acquire Interest in Joint Venture	$ 15
Advanced Safety and User Experience | Leddartech
Cost Method Investments			10
Payments to Acquire Interest in Joint Venture	$ 10
Advanced Safety and User Experience | Otonomo
Cost Method Investments			15
Payments to Acquire Interest in Joint Venture		$ 15
Advanced Safety and User Experience | Quanergy
Cost Method Investments			6
Signal and Power Solutions | Valens Semiconductor
Cost Method Investments			$ 10
Cost Method Investments, Original Cost						$ 10