Leases Components of Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 28, 2019	Sep. 28, 2019
Lease, Cost [Abstract]
Operating lease costs	$ 49	$ 145
Amortization of right-of-use assets	6	19
Interest on lease liabilities	2	5
Short-term lease costs	3	9
Variable lease costs	325	976
Sublease income	(4)	(11)
Total lease costs	$ 381	$ 1,143