Allowance For Doubtful Accounts (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year	$ 102	$ 117
Provision charged to expense	39	19
Accounts Receivable, Allowance for Credit Loss, Writeoff	(25)	(26)
Acquisitions, currency translation and other		(4)
Balance at End of Period	117	$ 106
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year	$ 1