Additional retainer amount paid each year to non-employee director under Director Compensation Program.

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Retainer amount paid each year to non-employee director under Director Compensation Program.

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- Definition

Represents the Maximum number of shares authorized for the incentive stock options for the equity based compensation plan.

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No definition available.

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- Definition

Number of equity instruments other than options that are vested and deferred as of the balance sheet date.

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No definition available.

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- Definition

The number of installments in which an employee award vests.

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No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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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.

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Note 13 - Equity-based Compensation (Details Textual)	12 Months Ended
Note 13 - Equity-based Compensation (Details Textual)	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 05, 2015 shares
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 3,700,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	4,080,000	$ 4,711,000
Restricted Stock Units (RSUs) [Member]
Allocated Share-based Compensation Expense, Total	$ 6,800,000	7,500,000	$ 9,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Share-based Compensation Arrangements by Share-based Payment Award, Vesting Period, Number of Installments	4
Annual Retainer	$ 75,000
Additional Annual Retainer	125,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 9,700,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 36 days
Restricted Stock Units (RSUs) [Member] \| Non-employee Directors [Member
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Vested and Deferred, Number \| shares	4,144
Stock Appreciation Rights (SARs) [Member]
Allocated Share-based Compensation Expense, Total	$ 3,700,000	3,300,000	2,900,000
Share-based Compensation Arrangements by Share-based Payment Award, Vesting Period, Number of Installments	4
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 6,300,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 36 days
Selling, General and Administrative Expenses [Member]
Allocated Share-based Compensation Expense, Total	$ 10,500,000	$ 10,700,000	$ 12,300,000
The 2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized \| shares				334,870
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Authorized for Incentive Stock Options \| shares				329,962
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant \| shares	236,547