Financial Instruments (Cash, Cash Equivalents, and Marketable Securities Fair Value Measurements) (Details) - Foreign Exchange Contract - USD ($) $ in Millions	9 Months Ended
	Sep. 26, 2020	Dec. 28, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount	$ 659	$ 739
Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, term of contract	12 months
Contracts not designated as hedging instruments:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, term of contract	3 months