Note 19 - Stock-based Compensation - Unvested Performance Stock Awards (Details) - $ / shares |
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|||||||
| Balance (in shares) | 216,905 | ||||||||
| Performance Stock Awards [Member] | |||||||||
| Balance (in shares) | 216,820 | 217,318 | 204,980 | ||||||
| Balance, Weighted average grant date fair value (in dollars per share) | $ 15.07 | $ 13.41 | $ 11.90 | ||||||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 45,346 | 92,474 | 71,184 | ||||||
| Granted, Weighted average grant date fair value (in dollars per share) | $ 28.34 | $ 16.42 | $ 15.05 | ||||||
| Vested, Shares (in shares) | (56,890) | (44,242) | (56,946) | ||||||
| Vested, Weighted average grant date fair value (in dollars per share) | $ 13.38 | $ 11.80 | $ 10.07 | ||||||
| Non-vesting, Shares (in shares) | [1] | (10,088) | (25,929) | [2] | |||||
| Non-vesting, Weighted average grant date fair value (in dollars per share) | [1] | $ 13.38 | $ 11.80 | ||||||
| Forfeited, Shares (in shares) | (2,344) | (22,801) | (1,900) | ||||||
| Forfeited, Weighted average grant date fair value (in dollars per share) | $ 15.37 | $ 14.75 | $ 12.32 | ||||||
| Balance (in shares) | 192,844 | 216,820 | 217,318 | ||||||
| Balance, Weighted average grant date fair value (in dollars per share) | $ 18.77 | $ 15.07 | $ 13.41 | ||||||
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