Net Gains or Losses Recognized on Economic Exposures Associated With Foreign Currency Exchange Contracts (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Costs and Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	$ 17	$ (233)
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	(14)	221
Net gains (losses)	3	(12)
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	3	7
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	(1)	(7)
Net gains (losses)	2	0
Income Taxes
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	3	23
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	(1)	(31)
Net gains (losses)	$ 2	$ (8)