Basis of Presentation - Recent Accounting Pronouncements (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jan. 01, 2018	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment out of operating earnings		$ 257	$ 224	$ 433	$ 323
Reclassification adjustment to other expense		$ 0	$ 4	$ 9	$ 11
Forecast | Accounting Standards Update 2017-07, Year 2017 Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment out of operating earnings	$ 37
Reclassification adjustment to other expense	37
Forecast | Accounting Standards Update 2017-07, Year 2016 Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment out of operating earnings	29
Reclassification adjustment to other expense	$ 29