Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 26, 2011
Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit	$ 250,000
Maturity date	May 04, 2016
Terms	LIBOR plus 125 basis points at the time of the respective borrowing.
Line of credit facility, amount outstanding	7,000
Outstanding letters of credit	43,200
Amount available for borrowing	199,800
Prior Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit	225,000
Maturity date	Sep. 13, 2011
Floating Rate Note [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 14, 2013
Terms	LIBOR plus 50 basis points
Issuance of floating rate notes	$ 100,000
Debt instrument, maturity date range end	two years