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Note 15 - Share-Based and Other Compensation Plans (Non-Qualified Stock Options) (Details) $ / shares in Units, $ in Thousands | 12 Months Ended
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Dec. 31, 2015 USD ($) days $ / shares shares | Dec. 31, 2014 USD ($) $ / shares shares | Dec. 31, 2013 USD ($) $ / shares shares
Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | shares |  | 1,435,232 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] |  |  |  |
Outstanding, Beginning of Period, Number of Shares | shares |  | 3,029,348 |  |
Outstanding, Beginning of Period, Weighted Average Exercise Price Per Share |  | $ 5.46 |  |
Granted, Number of Shares | shares |  | 212,230 | 289,500 | 279,650
Granted, Weighted Average Exercise Price Per Share |  | $ 18.42 |  |
Exercised, Number of Shares | shares |  | (496,496) |  |
Exercised, Weighted Average Exercise Price Per Share |  | $ 2.59 |  |
Forfeited, Number of Shares | shares |  | (52,625) |  |
Forfeited, Weighted Average Exercise Price Per Share |  | $ 8.89 |  |
Expired, Number of Shares | shares |  | 0 |  |
Expired, Weighted Average Exercise Price Per Share |  | $ 0.00 |  |
Outstanding, End of Period, Number of Shares | shares |  | 2,692,457 | 3,029,348 |
Outstanding, End of Period, Weighted Average Exercise Price Per Share |  | $ 6.94 | $ 5.46 |
Exercisable, Number of Shares | shares |  | 1,435,232 |  |
Exercisable, Weighted Average Exercise Price Per Share |  | $ 4.44 |  |
Available for grant | shares |  | 2,803,988 |  |
Weighted average fair value per share of stock options granted |  | $ 14.68 | $ 12.18 | $ 10.95
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options | $ |  | $ 1,280 | $ 260 | $ 60
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options | $ |  | 2,500 | 70 | 60
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | $ |  | 7,150 | 190 | 170
Total intrinsic value of options outstanding | $ |  | 19,100 | $ 34,100 | $ 27,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] |  |  |  |
Fair value of options vested during the year | $ |  | 3,400 |  |
Aggregate intrinsic value (excess market price over exercise price) | $ |  | $ 12,900 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term |  | 4 years 1 month 21 days |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Risk-free interest rate | [1] | 2.32% | 2.57% | 1.96%
Volatility | [2] | 93.70% | 94.26% | 94.63%
Dividend yield |  | 0.05% | 0.07% | 0.07%
Number of Consecutive Trading Days For Current Year Options Granted Vesting Requirement | days |  | 10 |  |
Share-based Compensation Arrangements, Windfall Tax Benefit, Threshold Amount | $ |  | $ 20,200 |  |
Equity Compensation Plan, 2014 [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] |  |  |  |
Available for grant | shares |  | 2,803,988 |  |
Maximum [Member] | Derived Service Period [Member] | Equity Compensation Plan, 2008 [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Expected life (years) |  |  | 3 years 350 days | 4 years
Maximum [Member] | Derived Service Period [Member] | Equity Compensation Plan, 2014 [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Expected life (years) |  | 4 years |  |
Minimum [Member] | Derived Service Period [Member] | Equity Compensation Plan, 2008 [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Expected life (years) |  |  | 2 years 360 days | 3 years 9 days
Minimum [Member] | Derived Service Period [Member] | Equity Compensation Plan, 2014 [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Expected life (years) |  | 3 years 9 days |  |
2014 Award Year [Member] | Minimum [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Closing Price of Common Stock Vesting Criteria |  | $ 23.03 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Percent of Increase Over Granted Price for Additional Vesting Criteria |  | 125.00% |  |
2013 Award Year [Member] | Minimum [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Closing Price of Common Stock Vesting Criteria |  |  | $ 19.30 |
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Percent of Increase Over Granted Price for Additional Vesting Criteria |  |  | 125.00% |
2012 Award Year [Member] | Minimum [Member] | Stock Options [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Closing Price of Common Stock Vesting Criteria |  |  |  | $ 17.49
Share-based Compensation Arrangement by Share-based Payment Award, Options Granted in Period, Percent of Increase Over Granted Price for Additional Vesting Criteria |  |  |  | 125.00%
[1] | The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant.
[2] | Volatility is determined at the date of grant using historical share price volatility and expected life of each award.

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- Definition The closing price per share of common stock on the NYSE that would need to be met for ten consecutive days either ending on or following the third year anniversary of the date of grant as an additional vesting criteria. + References No definition available. + Details
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- Definition The percentage increase over granted price based on the NYSE that our common stock must have for 10 consecutive trading days ending on or after the third anniversary of the date of grant for our stock options granted in the current period in order to complete the vesting criteria. + References No definition available. + Details
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- Definition Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.D.2) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section D -Subsection 2 + Details
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- Definition Weighted average remaining contractual term for fully vested and expected to vest options that are exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of share options (or share units) exercised during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28,29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
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