Share-Based Payments - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	May 10, 2014	May 04, 2013	May 10, 2014	May 04, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Total share-based compensation expense related to stock options and share purchase plans	$ 8.3	$ 9.0	$ 29.0	$ 25.6
Stock options exercised - Shares			194,130	638,553
Stock options exercised - Weighted average exercise price			$ 177.95	$ 129.50
Stock options granted			347,615	364,160
Weighted average grant date fair value of options granted			$ 96.92	$ 98.58
Anti-dilutive shares excluded from the computation of earnings per share	0	8,600	0	29,600