Note 11 - Employee Benefit Plans - Stock Option Activity (Details) - 2011 Equity Incentive Plan [Member] - $ / shares
|
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Outstanding, beginning of year, shares (in shares) |
479,594
|
322,086
|
220,500
|
| Outstanding, beginning of year, weighted average exercise price (in dollars per share) |
$ 16.31
|
$ 17.40
|
$ 14.57
|
| Granted, shares (in shares) |
0
|
0
|
0
|
| Granted, weighted average exercise price (in dollars per share) |
$ 0
|
$ 0
|
$ 0
|
| Assumed, shares (in shares) |
|
204,807
|
102,586
|
| Assumed, weighted average exercise price (in dollars per share) |
|
$ 14.12
|
$ 23.45
|
| Exercised, shares (in shares) |
(90,052)
|
(47,299)
|
(1,000)
|
| Exercised, weighted average exercise price (in dollars per share) |
$ 14.78
|
$ 14.21
|
$ 14.57
|
| Forfeited, shares (in shares) |
(289)
|
0
|
0
|
| Forfeited, weighted average exercise price (in dollars per share) |
$ 24.22
|
$ 0
|
$ 0
|
| Oustanding, end of year, shares (in shares) |
389,253
|
479,594
|
322,086
|
| Oustanding, end of year, weighted average exercise price (in dollars per share) |
$ 16.66
|
$ 16.31
|
$ 17.40
|
| Exercisable, end of year, shares (in shares) |
389,253
|
479,594
|
322,086
|
| Exercisable, end of year, weighted average exercise price (in dollars per share) |
$ 16.66
|
$ 16.31
|
$ 17.40
|