Note 2 - Summary of Significant Accounting Policies - Weighted-average Shares for Earnings Per Share Calculation (Details) - shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Weighted-average number of common shares outstanding excluding unvested restricted shares (in shares) | 52,450,780 | 43,939,039 | 43,924,457 |
| Effect of dilutive stock options and unvested shares (in shares) | 399,837 | 365,849 | 322,543 |
| Weighted-average number of common shares and dilutive potential common shares outstanding (in shares) | 52,850,617 | 44,304,888 | 44,247,000 |