Shareholders' Equity (Additional Information) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Oct. 25, 2014	Oct. 26, 2013	Oct. 25, 2014 Stock repurchase program	Jul. 26, 2014 Stock repurchase program
Class of Stock [Line Items]
Cash dividends paid per common share (in dollars per share)	$ 0.19	$ 0.17
Payments of Dividends	$ 973,000,000	$ 914,000,000
Authorized common stock repurchase amount	97,000,000,000
Remaining authorized repurchase amount	7,500,000,000
Accrued Liabilities, Current			51,000,000	126,000,000
Shares Paid for Tax Withholding for Share Based Compensation (in shares)	14	12
Payments Related to Tax Withholding for Share-based Compensation	$ 342,000,000	$ 286,000,000