Note 4 - Fair Value Measurements - Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Feb. 25, 2017	Aug. 27, 2016
Cash equivalents	$ 224,756	$ 172,760
Pension plan assets	4,817	4,753
Foreign currency forward contracts	220	188
Total assets at fair value	229,793	177,701
Fair Value, Inputs, Level 1 [Member]
Cash equivalents	224,756	172,760
Pension plan assets
Foreign currency forward contracts
Total assets at fair value	224,756	172,760
Fair Value, Inputs, Level 2 [Member]
Cash equivalents
Pension plan assets	4,817	4,753
Foreign currency forward contracts	220	188
Total assets at fair value	$ 5,037	$ 4,941