Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 27, 2020	Mar. 28, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0		$ 0	$ 0	$ 1
Interest cost	2		16	19	48
Expected return on plan assets	0		(14)	(15)	(43)
Amortization of Net actuarial loss	1		0	3	1
Amortization of prior service credit	1		1	1	1
Settlement (gain) loss	(6)	$ 110	0	(112)	19
Net periodic cost (credit)	(2)		3	(104)	27
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	1		0	1	1
Amortization of prior service credit	0		(1)	(1)	(6)
Net periodic cost (credit)	$ 1		$ (1)	$ 0	$ (5)