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Note 12 - Share-based Compensation (Details Textual) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Number Of Active Stock Incentive Plans | 1 |  |  |
Number Of Inactive Stock Option Plans | 1 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures | 0 |  | 0 | 0
Common Stock, Capital Shares Reserved for Future Issuance | 557,098 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | $ 0 |  | $ 0 | $ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | 0 |  |  |
Restricted Stock Units and Performance Share Award Target Level, Percentage | 100.00% |  |  |
Minimum Performance Awards Issued Multiplier | 0.00% |  |  |
Maximum Performance Awards Issued Multiplier | 200.00% |  |  |
Director [Member] |  |  |  |
Share-based Goods and Nonemployee Services Transaction, Quantity of Securities Issued | 27,640 |  | 10,464 | 9,150
Share Based Compensation Arrangement by Stock Based Payment Award Grant Date Fair Value | $ 9.95 |  | $ 21.02 |
Director [Member] | Minimum [Member] |  |  |  |
Share Based Compensation Arrangement by Stock Based Payment Award Grant Date Fair Value |  |  |  | $ 36
Director [Member] | Maximum [Member] |  |  |  |
Share Based Compensation Arrangement by Stock Based Payment Award Grant Date Fair Value |  |  |  | 36.41
Employee Stock Option [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 5 years |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period | 10 years |  |  |
Restricted Stock Units (RSUs) [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 3 years |  |  |
Performance Shares [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 3 years |  |  |
Restricted Stock Units and Performance Stock Awards [Member] |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | $ 1,000,000 |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | 1 year |  |  |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number At Target Level Of Performance | 47,000 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 9.50 |  | $ 0 | $ 41.76
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 169,583 | [1] | 0 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $ 100,000 |  | $ 1,600,000 | $ 3,500,000
[1] | The number of shares disclosed in this table are at the target level of 100%.

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