Share-Based Payments (Tables)

3 Months Ended

Nov. 18, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Weighted Average for Key Assumptions Used in Determining Fair Value of Options Granted and Related Share-Based Compensation Expense

The weighted average fair value of the stock option awards granted during the twelve week periods ended November 18, 2017, and November 19, 2016, using the Black-Scholes-Merton multiple-option pricing valuation model, was $128.93 and $139.66 per share, respectively, using the following weighted average key assumptions:

	Twelve Weeks Ended
	November 18, 2017		November 19, 2016
Expected price volatility		20%		18%
Risk-free interest rate		1.9%		1.2%
Weighted average expected lives (in years)		5.1		5.1
Forfeiture rate		10%		10%
Dividend yield		0%		0%