Special Charges - Restructuring reserve activity and total expected cash outlay (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jul. 04, 2020	Jan. 04, 2020	Dec. 29, 2018
Special Charges
Remaining expected cash payments for restructuring activities	$ 65
Restructuring reserve activity
Balance at beginning of period	65	$ 40	$ 44
Cash paid		(31)	(30)
Foreign currency translation		(1)
Balance at end of period		65	40
Severance Costs
Restructuring reserve activity
Balance at beginning of period	46	8	24
Cash paid		(8)	(21)
(Reversals)/provision for prior plans			(3)
Balance at end of period		46	8
Contract Terminations and Other
Restructuring reserve activity
Balance at beginning of period	$ 19	32	20
Cash paid		(23)	(9)
(Reversals)/provision for prior plans			3
Foreign currency translation		(1)
Balance at end of period		19	32
2018 Restructuring Plan
Restructuring reserve activity
Provision for plan			26
2018 Restructuring Plan | Severance Costs
Restructuring reserve activity
Provision for plan			8
2018 Restructuring Plan | Contract Terminations and Other
Restructuring reserve activity
Provision for plan			$ 18
2019 Restructuring Plan
Restructuring reserve activity
Provision for plan		57
2019 Restructuring Plan | Severance Costs
Restructuring reserve activity
Provision for plan		46
2019 Restructuring Plan | Contract Terminations and Other
Restructuring reserve activity
Provision for plan		$ 11