Financial Instruments - Notional Amounts and Credit Risk Amounts Associated with Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 30, 2019	Sep. 29, 2018
Derivatives designated as accounting hedges | Foreign exchange contracts
Derivative [Line Items]
Derivative, notional amount	$ 52,660	$ 65,368
Derivative, credit risk amount	1,364	1,015
Derivatives designated as accounting hedges | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	33,250	33,250
Derivative, credit risk amount	68	0
Derivatives not designated as accounting hedges | Foreign exchange contracts
Derivative [Line Items]
Derivative, notional amount	63,477	63,062
Derivative, credit risk amount	$ 216	$ 259