Shareholders' Equity (Stock Repurchase Program) (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended
	Jan. 25, 2014
Stock Repurchase Program [Roll Forward]
Cumulative shares repurchased, beginning balance	3,868
Repurchase of common stock under the stock repurchase program (1)	269
Cumulative shares repurchased, ending balance	4,137
Cumulative weighted-average price per share, beginning balance	$ 20.40
Weighted Average Price Per Share Of Stock Repurchased In Period	$ 22.33
Cumulative weighted-average price per share, ending balance	$ 20.53
Cumulative amount repurchased, beginning balance	$ 78,906
Repurchase of common stock under the stock repurchase program, amount	6,020
Cumulative amount repurchased, ending balance	$ 84,926