Income Taxes - Tax Reconciliation Narrative (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Jun. 28, 2019	Sep. 28, 2018	Dec. 29, 2017	Sep. 27, 2019	Sep. 28, 2018	Sep. 29, 2017
Significant components of the income tax provision (benefit)
Income tax benefit related to tax impacts of Swiss Tax Reform	$ 214			$ 216
Income tax benefit related to a tax settlement in a non-U.S. jurisdictions	$ 93			90
Net income tax benefit (expense) associated with certain legal entity restructurings and intercompany transactions		$ 1,222		$ (15)
Increase in valuation allowance for certain U.S. federal tax credit carryforwards		$ 46
Income tax expense related to tax impacts of the Tax Cuts and Jobs Act			$ 567		$ 567
Net income tax benefit related to certain legal entity restructurings			$ 61
Income tax benefit associated with intercompany transactions and the corresponding reduction in the valuation allowance for U.S. tax loss carryforwards						$ 52
Income tax benefit associated with pre-separation tax matters						14
ASU 2016-09
Significant components of the income tax provision (benefit)
Income tax benefit related to share-based payments and adoption of ASU 2016-09						$ 40