Stock-Based Compensation (Time-Lapse Restricted Stock Units, EPS Performance Restricted Stock Units And Strategic Performance Restricted Stock Units And TSR Performance Restricted Stock Units) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jan. 29, 2012	Jan. 30, 2011
Time Lapse, EPS And Strategic Performance Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Units	2,710
Granted, Units	2,611
Vested, Units	(1,133)
Forfeited, Units	(156)
Nonvested at end of period, Units	4,032
Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value	$ 35.11
Granted, Weighted-Average Grant-Date Fair Value	$ 32.38	$ 36.08
Vested, Weighted-Average Grant-Date Fair Value	$ 35.80
Forfeited, Weighted-Average Grant-Date Fair Value	$ 33.39
Nonvested at end of period, Weighted-Average Grant-Date Fair Value	$ 33.21
TSR Performance Restricted Stock/Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at beginning of period, Units	3,431
Granted, Units	0
Vested, Units	0
Forfeited, Units	(1,258)
Nonvested at end of period, Units	2,173
Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value	$ 40.78
Granted, Weighted-Average Grant-Date Fair Value	$ 0.00	$ 43.18
Vested, Weighted-Average Grant-Date Fair Value	$ 0.00
Forfeited, Weighted-Average Grant-Date Fair Value	$ 45.62
Nonvested at end of period, Weighted-Average Grant-Date Fair Value	$ 37.98