Note 4 - Fair Value Measurements - Fair Value of Financial Assets (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 30, 2017	Sep. 30, 2017
Cash equivalents	$ 37,771	$ 31,659
Cash surrender value of life insurance policies	9,435	9,026
Total	47,206	40,685
Fair Value, Inputs, Level 1 [Member]
Cash equivalents	37,771	31,659
Cash surrender value of life insurance policies
Total	37,771	31,659
Fair Value, Inputs, Level 2 [Member]
Cash equivalents
Cash surrender value of life insurance policies	9,435	9,026
Total	$ 9,435	$ 9,026