Pension and Other Postretirement Benefit Plans (Narrative) (Details) - Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019	Sep. 28, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 9	$ 9	$ 10	$ 12
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	106	$ 0	$ 106	$ (19)
Multiemployer Plans, Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ (110)
Qualified Plan [Member] | Funded Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount					$ 1,400