Note 5 - Derivative Instruments and Hedging Activities (Details Textual) CAD in Millions	3 Months Ended		9 Months Ended
	May 28, 2016 USD ($)	May 30, 2015 USD ($)	May 28, 2016 USD ($)	May 30, 2015 USD ($)	May 28, 2016 CAD	May 28, 2016 USD ($)	Feb. 27, 2016 USD ($)	Aug. 29, 2015 USD ($)	Feb. 28, 2015 USD ($)	Jan. 31, 2015 CAD Rate	Aug. 30, 2014 USD ($)
Forward Contracts [Member] | Other Noncurrent Assets [Member]
Cash Flow Hedge Derivative Instrument Assets at Fair Value						$ 100,000
Forward Contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Cash Flow Hedge Derivative Instrument Assets at Fair Value						100,000
Forward Contracts [Member]
Derivative, Number of Instruments Held										16
Derivative, Notional Amount | CAD					CAD 18.3					CAD 31.0
Accumulated Other Comprehensive Income (Loss), Net of Tax						100,000
Canadian Dollars to US Dollars [Member]
Derivative, Forward Exchange Rate | Rate										78.25%
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (20,984,000)		$ (20,984,000)		$ (25,001,000)	$ (28,427,000)	$ (24,413,000)	$ (21,335,000)		$ (2,533,000)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	$ 36,000	$ (70,000)	$ 201,000	$ (70,000)