Financial Instruments (Cash, Cash Equivalents, and Marketable Securities Fair Value Measurements) (Details) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 30, 2017
Schedule of Investments [Line Items]
Total Fair Value		$ 983	$ 1,185
Cash and Cash Equivalents		948	1,185
Short-Term Marketable Securities	[1]	35	0
Level 1
Schedule of Investments [Line Items]
Total Fair Value		95	395
Cash and Cash Equivalents		95	395
Short-Term Marketable Securities		0
Level 2
Schedule of Investments [Line Items]
Total Fair Value		842	682
Cash and Cash Equivalents		807	682
Short-Term Marketable Securities		35
Cash
Schedule of Investments [Line Items]
Total Fair Value		46	108
Cash and Cash Equivalents		46	108
Short-Term Marketable Securities		0
Government money market funds | Level 1
Schedule of Investments [Line Items]
Total Fair Value		95	395
Cash and Cash Equivalents		95	395
Short-Term Marketable Securities		0
Commercial paper | Level 2
Schedule of Investments [Line Items]
Total Fair Value		842	682
Cash and Cash Equivalents		807	$ 682
Short-Term Marketable Securities		$ 35

[1] Prior year amounts adjusted to reflect the retrospective application of ASU 2014-09, Revenue from Contracts with Customers. Refer to Note 1.