Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Components of Notes Payable

	June 30, 2018				December 30, 2017
(millions)	Principal amount		Effective interest rate		Principal amount		Effective interest rate (a)
U.S. commercial paper	$	197	2.26	%	$	196	1.76	%
Europe commercial paper	—		—	%	96		(0.32	)%
Bank borrowings	127				78
Total	$	324			$	370

(a) Negative effective interest rates on certain borrowings in Europe are the result of efforts by the European Central Bank to stimulate the economy in the eurozone.