Share Repurchase Programs (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended				3 Months Ended	6 Months Ended
	Jan. 29, 2012	Jan. 30, 2011	Jan. 29, 2012 Capital Stock In Treasury [Member]	Jan. 30, 2011 Capital Stock In Treasury [Member]	Jul. 31, 2011 June 2011 Program [Member]	Jan. 29, 2012 June 2011 Program [Member]	Jan. 29, 2012 June 2011 Program [Member] Capital Stock In Treasury [Member]	Jan. 30, 2011 June 2008 Program [Member] Capital Stock In Treasury [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized amount for shares repurchase					$ 1,000
Shares repurchased, shares			5	16
Shares repurchased, value	173	573	173	573			115	456
Amount available for share repurchase program						$ 885