Derivative Instruments - Effect of Derivative Instruments Not Designated as Hedges on Consolidated Statement of Operations Summary (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 25, 2020	Apr. 27, 2019	Apr. 25, 2020	Apr. 27, 2019
Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	$ 0	$ 0	$ 2	$ (1)
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	0	0	1	(1)
Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	(157)	14	(120)	(57)
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	(47)	(29)	(56)	(57)
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	(2)	(4)	(9)	(12)
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	(93)	42	(49)	9
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	(9)	4	(5)	1
Derivatives not designated as hedging instruments: | Equity derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses)	$ (6)	$ 1	$ (1)	$ 2