Financial Instruments - Notional Amounts and Credit Risk Amounts Associated with Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 29, 2019	Sep. 29, 2018
Derivatives designated as accounting hedges | Foreign exchange contracts
Derivative [Line Items]
Derivative, notional amount	$ 55,067	$ 65,368
Derivative, credit risk amount	1,179	1,015
Derivatives designated as accounting hedges | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	31,250	33,250
Derivative, credit risk amount	449	0
Derivatives not designated as accounting hedges | Foreign exchange contracts
Derivative [Line Items]
Derivative, notional amount	54,744	63,062
Derivative, credit risk amount	$ 184	$ 259