Indebtedness (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 28, 2019
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End	0.95%
General Discussion of Derivative Instruments and Hedging Activities	We are exposed to market risk from fluctuations in the variable interest rates on outstanding indebtedness under our Credit Agreement. In order to manage this exposure, we have entered into an interest rate swap agreement to hedge the variability of cash flows associated with such interest obligations. The interest rate swap is designated as a cash flow hedge, which effectively fixes the interest rate on the hedged indebtedness under our Credit Agreement at 3.06%
Derivative, Fair Value, Net	$ 41	$ 17
Debt Instrument, Amount Uncommitted and Available for Sale	1,500
Senior Notes - Series 2020-A due March 11, 2030
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 300
Debt Instrument, Interest Rate, Stated Percentage	2.50%
Debt Instrument, Maturity Date	Mar. 11, 2030
Debt Instrument, Frequency of Periodic Payment	payable semiannually
Debt Instrument, Date of First Required Payment	Sep. 11, 2020
Debt Instrument, Restrictive Covenants	The Series 2020-A Notes are subject to the terms of the 2019 Shelf Agreement, which contains customary events of default and covenants related to limitations on indebtedness and transactions with affiliates and the maintenance of certain financial ratios.