Postretirement Benefit Plans - Narrative (Details) - Pension - U.S. - USD ($)	3 Months Ended	6 Months Ended
	Sep. 27, 2019	Dec. 28, 2018	Dec. 29, 2017	Apr. 02, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary employer contributions	$ 302,000,000	$ 700,000,000	$ 700,000,000
Required employer contributions during the remainder of fiscal 2021				$ 0