Shareholders' Equity (Stock Repurchase Program) (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Oct. 24, 2015 USD ($) $ / shares shares
Stockholders' Equity Note [Abstract]
Cumulative Shares Repurchased, Beginning balance (in shares)	4,443	[1]
Repurchase of Common Stock During Period (in shares)	45	[2]
Cumulative Shares Repurchased, Ending balance (in shares)	4,488
Cumulative Weighted-Average Price per Share, Beginning balance, dollars per share | $ / shares	$ 20.86
Repurchase of common stock under the stock repurchase program, Weighted-Average Price per Share, dollars per share | $ / shares	26.83
Cumulative Weighted-Average Price per Share, Ending balance, dollars per share | $ / shares	$ 20.92
Cumulative Amount Repurchased, Beginning balance (in dollars) | $	$ 92,679	[1]
Stock Repurchased During the Period (in dollars) | $	1,207	[2]
Cumulative Amount Repurchased, Ending balance (in dollars) | $	$ 93,886

[1] There were $36 million of stock repurchases that were pending settlement as of July 25, 2015.

[2] Includes stock repurchases of $33 million, which were pending settlement as of October 24, 2015.