Shareholders' Equity (Stock Repurchase Program) (Details) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Jan. 23, 2016 USD ($) $ / shares shares
Stockholders' Equity Note [Abstract]
Cumulative Shares Repurchased, Beginning balance (in shares) | shares	4,443	[1]
Repurchase of Common Stock During Period (in shares) | shares	93
Cumulative Shares Repurchased, Ending balance (in shares) | shares	4,536
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	26.46
Cumulative Weighted-Average Price per Share, Ending balance, dollars per share | $ / shares	$ 20.97
Cumulative Amount Repurchased, Beginning balance (in dollars) | $	$ 92,679	[1]
Stock Repurchased During the Period (in dollars) | $	2,469	[2]
Cumulative Amount Repurchased, Ending balance (in dollars) | $	$ 95,148

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

[2] Includes stock repurchases of $161 million, which were pending settlement as of January 23, 2016.