Net Gains or Losses Recognized on Economic Exposures Associated With Foreign Currency Exchange Contracts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Costs and Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	$ 64	$ 110	$ 81	$ (123)
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	(77)	(103)	(91)	118
Net gains (losses)	(13)	7	(10)	(5)
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	24	(3)	27	4
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	(27)	3	(28)	(4)
Net gains (losses)	(3)	0	(1)	0
Income Taxes
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) on foreign currency denominated assets and liabilities	(15)	(11)	(12)	12
Net gains (losses) on foreign exchange risk management contracts not designated as hedges	17	14	16	(17)
Net gains (losses)	$ 2	$ 3	$ 4	$ (5)