Note 10 - Share-based Employee Compensation - Summary of Stock Option Activity (Details) - $ / shares
|
12 Months Ended |
Jun. 06, 2017 |
May 31, 2016 |
| Granted, Shares (in shares) |
|
0
|
| Stock Options Services-Based [Member] |
|
|
| Outstanding, Shares (in shares) |
2,066,000
|
|
| Outstanding, Weighted Average Exercise Price (in dollars per share) |
$ 7.89
|
|
| Granted, Shares (in shares) |
1,126,000
|
|
| Granted, Weighted Average Exercise Price (in dollars per share) |
$ 3.46
|
|
| Cancellations and Forfeitures, Shares (in shares) |
(50,000)
|
|
| Cancellations and Forfeitures, Weighted Average Exercise Price (in dollars per share) |
$ 4.49
|
|
| Expired, Shares (in shares) |
(1,448,000)
|
|
| Expired, Weighted Average Exercise Price (in dollars per share) |
$ 6.66
|
|
| Outstanding, Shares (in shares) |
1,694,000
|
2,066,000
|
| Outstanding, Weighted Average Exercise Price (in dollars per share) |
$ 6.09
|
$ 7.89
|
| Outstanding (Year) |
2 years 339 days
|
|
| Exercisable at end of year (in shares) |
1,224,000
|
|
| Exercisable at end of year (in dollars per share) |
$ 7
|
|
| Exercisable at end of year (Year) |
1 year 262 days
|
|