Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 25, 2020	Dec. 27, 2019
Income Taxes
Income tax expense	$ (60)	$ (447)
Income tax benefit from change in the tax method of depreciating or amortizing certain assets	29
Income tax (expense) benefit related to tax impacts of Swiss Tax Reform		$ (355)
Unrecognized income tax benefits, approximate amount that could be resolved in next twelve months	$ 50