Shareholders' Equity (Stock Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Stockholders' Equity Note [Abstract]
Repurchase of common stock under the stock repurchase program, Shares repurchased (in shares)	432	118	148
Cumulative weighted average price per share repurchased, Weighted average price per share (in dollars per share)	$ 40.88	$ 31.38	$ 26.45
Repurchase of common stock under the stock repurchase program, Amount repurchased	$ 17,661	$ 3,706	$ 3,918