Income Taxes (Income Before Provision for Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 27, 2019	Apr. 28, 2018
Income Tax Disclosure [Abstract]
Income before provision for income taxes	$ 3,615	$ 3,253	$ 10,867	$ 9,447
Provision for income taxes	$ 571	$ 562	$ 1,452	$ 13,140
Effective tax rate	15.80%	17.30%	13.40%	139.10%