Business And Geographic Segment Information Business And Geographic Segment Information (Geographic Information, Net Sales) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 28, 2013	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 29, 2012	Oct. 30, 2011	Jul. 28, 2013	Jul. 29, 2012	Jul. 31, 2011
Net Sales, Total	$ 1,723	$ 1,962	$ 2,162	$ 2,205	$ 1,519	$ 1,698	$ 1,943	$ 2,015	$ 8,052	$ 7,175	$ 7,143
UNITED STATES
Net Sales									6,195	5,359	5,309
AUSTRALIA
Net Sales									801	819	842
Other Countries [Member]
Net Sales									$ 1,056	$ 997	$ 992