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Benefit of tax deductions on grant date fair value.

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The expense resulting from the benefit (short-fall) of tax deductions from share-based compensation, in excess of grant-date fair value.

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Maximum period of common stock granted

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The number of officers receiving a share-based compensation award.

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Total benefit of tax deductions.

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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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Unrecognized cost of unvested share-based compensation awards.

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- Definition

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

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

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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 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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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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 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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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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- Definition

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

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No definition available.

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Number of share options (or share units) exercised during the current period.

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Note 18 - Equity Incentive Plans (Details Textual)	1 Months Ended			12 Months Ended				36 Months Ended
Note 18 - Equity Incentive Plans (Details Textual)	Dec. 31, 2016 shares	Dec. 31, 2015 shares	Dec. 31, 2014 shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2013 shares	Dec. 31, 2017 USD ($) shares	May 31, 2015 shares
Proceeds from Stock Options Exercised \| $				$ 1,094,000	$ 7,661,000	$ 5,014,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period				46,790	327,830	214,580
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value \| $				$ 663,000	$ 4,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized \| $				$ 9,500,000				$ 9,500,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition				2 years
Benefit (Shortfall) of Tax Deductions from Share-based Compensation \| $						$ (5,400,000)
Benefit Of Tax Deductions On Grant Date Fair Value \| $						6,500,000
Total Benefit Of Tax Deductions \| $						$ 1,100,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				87,781	88,693	72,900
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value \| $ / shares				$ 38.59	$ 30.37	$ 28.11
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 years
Number of Officers Receiving Award	7	7	7	6			8
Allocated Share-based Compensation Expense \| $				$ 5,200,000	$ 4,400,000	$ 4,500,000
Performance TSR Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	30,319	61,209	60,456	23,556			119,840
Performance EPS Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	58,241	57,409	57,642				116,186
Performance ROA Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	29,119			22,377
Two Thousand Five Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized									3,562,168
Maximum Period Of Common Stock Granted				10 years
Annual Increments To Be Vested In Common Stock Units				20.00%				20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross								0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant				2,776,289				2,776,289