Shareholders' Equity (Stock Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Oct. 27, 2018	Jul. 28, 2018	Apr. 28, 2018	Jan. 27, 2018	Oct. 28, 2017
Stockholders' Equity Note [Abstract]
Repurchase of common stock under the stock repurchase program, Shares Repurchased (in shares)	109	138	140	103	51
Repurchase of common stock under the stock repurchase program, Weighted-Average Price per Share (in dollars per share)	$ 46.01	$ 43.58	$ 42.83	$ 39.07	$ 31.80
Repurchase of common stock under the stock repurchase program, Amount Repurchased	$ 5,026	$ 6,015	$ 6,015	$ 4,011	$ 1,620