Shareholders' Equity (Narrative) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended	6 Months Ended
	Feb. 07, 2012	Jan. 28, 2012	Jan. 28, 2012	Jan. 29, 2011
Shareholders' Equity [Abstract]
Authorized common stock repurchase amount		$ 82,000,000,000	$ 82,000,000,000
Remaining authorized repurchase amount		8,200,000,000	8,200,000,000
Cash dividends declared and paid per common share		$ 0.06	$ 0.12
Cash dividends paid			644,000,000
Shares repurchased in settlement of employee tax withholding obligations			9	7
Dollar value of Shares repurchased in settlement of employee tax withholding obligations			$ 145,000,000	$ 140,000,000
Cash dividends declared, increase over previous quarter's dividend, cents	$ 0.02
Cash dividends declared per common share	$ 0.08
Cash dividends date declared	Feb. 07, 2012
Cash dividends date to be paid	Apr. 25, 2012
Cash dividends date of shareholder record	Apr. 05, 2012