Net Gains or Losses Recognized on Economic Exposures Associated With Foreign Currency Exchange Contracts (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Costs and Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on foreign currency denominated assets and liabilities	$ 69	$ (27)
Net gain (loss) on foreign exchange risk management contracts not designated as hedges	(80)	24
Net gain (loss)	(11)	(3)
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on foreign currency denominated assets and liabilities	(12)	40
Net gain (loss) on foreign exchange risk management contracts not designated as hedges	10	(39)
Net gain (loss)	(2)	1
Income Taxes
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on foreign currency denominated assets and liabilities	(15)	15
Net gain (loss) on foreign exchange risk management contracts not designated as hedges	17	(18)
Net gain (loss)	$ 2	$ (3)