Note 13 - Stock-based Compensation and Similar Arrangement - Stock Option Activity (Details)
$ / shares in Units, $ in Thousands |
12 Months Ended |
|
Dec. 31, 2016
USD ($)
$ / shares
shares
|
|---|
| Balance at beginning of period (in shares) | shares |
505,452
|
| Balance at beginning of period (in dollars per share) | $ / shares |
$ 34.84
|
| Exercised (in shares) | shares |
(105,788)
|
| Exercised (in dollars per share) | $ / shares |
$ 38.83
|
| Forfeited/Cancelled (in shares) | shares |
(27,400)
|
| Forfeited/Cancelled (in dollars per share) | $ / shares |
$ 31.48
|
| Expired (in shares) | shares |
(16,666)
|
| Expired (in dollars per share) | $ / shares |
$ 43.81
|
| Outstanding at end of period (in shares) | shares |
355,598
|
| Outstanding at end of period (in dollars per share) | $ / shares |
$ 33.48
|
| Outstanding at end of period (Year) |
3 years 149 days
|
| Outstanding at end of period | $ |
$ 2,514
|
| Vested or expected to vest at end of period (in shares) | shares |
344,574
|
| Vested or expected to vest at end of period (in dollars per share) | $ / shares |
$ 33.33
|
| Vested or expected to vest at end of period (Year) |
3 years 167 days
|
| Vested or expected to vest at end of period | $ |
$ 2,500
|
| Exercisable at end of period (in shares) | shares |
232,141
|
| Exercisable at end of period (in dollars per share) | $ / shares |
$ 30.86
|
| Exercisable at end of period (Year) |
4 years 80 days
|
| Exercisable at end of period | $ |
$ 2,355
|