Revenues - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 31, 2018
Capitalized Contract Cost [Line Items]
Remaining performance obligation	$ 687		$ 687		$ 489
Remaining performance obligation, expected recognition period	2 years		2 years
Increase driven by payments received or due in advance of satisfying performance obligations	$ 418		$ 418		382
Revenue recognized that was included in contract liability	57	$ 55	127	$ 120
Prepaid expenses and other current assets
Capitalized Contract Cost [Line Items]
Contract assets recorded in prepaids and other current assets	$ 7		$ 7		$ 5