Note 12 - Fair Value Measurements - Fair Values of Financial Assets and Liabilities Measured on a Recurring Basis (Details) - Fair Value, Inputs, Level 1 [Member] - USD ($) $ in Thousands |
Jun. 06, 2017 |
May 31, 2016 |
|---|---|---|
| Deferred compensation plan – Assets | $ 5,631 | $ 6,660 |
| Deferred compensation plan – Liabilities | $ (5,631) | $ (6,660) |