Share-Based Payments (Tables)

3 Months Ended

Nov. 17, 2018

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 17, 2018 and November 18, 2017, using the Black-Scholes-Merton multiple-option pricing valuation model, was $208.31 and $128.93 per share, respectively, using the following weighted average key assumptions:

	Twelve Weeks Ended
	November 17,         2018		November 18,       2017
Expected price volatility		21%		20%
Risk-free interest rate		3.1%		1.9%
Weighted average expected lives (in years)		5.6		5.1
Forfeiture rate		10%		10%
Dividend yield		0%		0%