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Share-Based Payments - Weighted Average for Key Assumptions Used in Determining Fair Value of Options Granted and Related Share-Based Compensation Expense (Detail)
6 Months Ended
Feb. 15, 2014
Feb. 09, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Expected price volatility 23.00% 29.00%
Risk-free interest rate 1.00% 0.50%
Weighted average expected lives (in years) 5 years 2 months 12 days 5 years 2 months 12 days
Forfeiture rate 9.00% 10.00%
Dividend yield 0.00% 0.00%