Financial Instruments (Cash, Cash Equivalents, and Marketable Securities Fair Value Measurements) (Details) - USD ($) $ in Millions	Jun. 29, 2019	Dec. 29, 2018
Schedule of Investments [Line Items]
Total Fair Value	$ 1,128	$ 1,156
Cash and Cash Equivalents	963	1,078
Short-Term Marketable Securities	165	78
Level 1
Schedule of Investments [Line Items]
Total Fair Value	1	275
Cash and Cash Equivalents	1	275
Short-Term Marketable Securities	0	0
Level 2
Schedule of Investments [Line Items]
Total Fair Value	185	566
Cash and Cash Equivalents	20	488
Short-Term Marketable Securities	165	78
Cash
Schedule of Investments [Line Items]
Total Fair Value	942	315
Cash and Cash Equivalents	942	315
Short-Term Marketable Securities	0	0
Government money market funds | Level 1
Schedule of Investments [Line Items]
Total Fair Value	1	275
Cash and Cash Equivalents	1	275
Short-Term Marketable Securities	0	0
Commercial paper | Level 2
Schedule of Investments [Line Items]
Total Fair Value	185	566
Cash and Cash Equivalents	20	488
Short-Term Marketable Securities	$ 165	$ 78