Borrowings - Narrative (Details) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017
Debt Disclosure [Abstract]
Excess of fair value over carrying value of debt	$ 2.0	$ 1.6
Line of Credit Facility, Initiation Date	Sep. 14, 2017
Borrowing capacity under credit facility	$ 10.0
Line of Credit Facility, Expiration Date	Sep. 13, 2018
Short-term borrowings and the current portion of long-term debt	$ 3.9	4.7
Borrowed under the commercial paper program	2.3	2.7
Current portion of long term debt	$ 1.5	$ 1.7