Reorganization of Business - Net Charges Incurred by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Restructuring Cost and Reserve [Line Items]
Reorganization of business charges	$ 8	$ 7	$ 30	$ 74
Products
Restructuring Cost and Reserve [Line Items]
Reorganization of business charges	6	5	22	59
Services
Restructuring Cost and Reserve [Line Items]
Reorganization of business charges	$ 2	$ 2	$ 8	$ 15