Represents expected volatility rate period for share based payment award by share based payment.

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Fair value of non-vested equity-based payment instruments, excluding stock (or unit) options, vested.

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Represents historical volatility for fair value assumptions for share-based payment award by share based compensation.

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Percent of shares that may be issued in accordance with the plan as a proportion of outstanding awards.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Aggregate number of common shares reserved for future issuance.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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- Definition

Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.

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No definition available.

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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.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Number of shares authorized for issuance under share-based payment arrangement.

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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.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Intrinsic value of outstanding award under share-based payment arrangement. Excludes share and unit options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Note 11 - Share-based Compensation (Details Textual) - USD ($)			12 Months Ended
	Apr. 01, 2019	Feb. 25, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 31, 2017	Dec. 31, 2013
Share-based Payment Arrangement, Expense			$ 3,043,000	$ 1,519,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)			5 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)			737,497	964,997	999,997
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)			429,399	279,919	237,926
Share-based Payment Arrangement, Expense			$ 1,200,000	$ 413,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total			$ 4,900,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			3 years 109 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Fair Value			$ 5,300,000	1,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 1,900,000	$ 1,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)			309,218	181,268
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)			1,570,455	2,043,402	2,390,012
Share-based Payment Arrangement, Expense			$ 370,000	$ 509,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value			22,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value			20,900,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 7,100,000	$ 3,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)			5 years	5 years 146 days
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total			$ 148,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			1 year 36 days
Market-based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)	29,604	94,247
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance			69.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			2.50%
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			2 years
Market-based Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards			0.00%
Market-based Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards			200.00%
Performance-based Restricted Stock [Member]
Share-based Payment Arrangement, Expense			$ 1,500,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total			$ 1,800,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding			$ 3,300,000
The 2013 Performance Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)			2,100,000
The 2013 Performance Incentive Plan [Member] \| Performance Shares [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)						4,100,000	3,100,000
The 2013 Performance Incentive Plan [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)			553,000
All Other Unapproved Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)			188,000
Management Performance Bonus Plan 2017 [Member] \| Performance Shares [Member]
Share-based Payment Arrangement, Expense			$ 0	$ 509,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value			10,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 3,700,000	$ 285,000,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)					1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price (in dollars per share)					$ 1.64
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number (in shares)				999,997	999,997
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Year)			2 years