Business Combinations (Additional Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 25, 2014	Oct. 25, 2014 General and administrative	Oct. 26, 2013 General and administrative
Supplementary Information [Line Items]
Number of business combinations (in numbers)	2
Acquired Cash and Cash Equivalents	$ 3
Business Acquisition, Transaction Costs		$ 2	$ 6