Stock-Based Compensation (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares representing outstanding award	37,350
Deferred income tax expense (benefit)	$ (1,761)	$ (1,096)	$ (113)
Unrecognized compensation cost	$ 100
Weighted average remaining service period of nonvested awards	6 months 28 days
Proceeds from issuance of common stock	$ 145	$ 148	$ 102
Number of stock options settled for fully vested shares	30,700	104,000	327,100
Number of shares issued in settlement of stock option	9,976	46,432	140,544
Intrinsic value of stock options exercised	$ 500	$ 2,300	$ 7,000
Income tax benefits	$ 9,787	10,834	15,725
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	66,019
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred income tax expense (benefit)	$ 1,200	1,100	700
Equity Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefits	$ 100	800	2,500
2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,355,764
Shares reserved for future issuance	729,095
Number of outstanding awards	361,610
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 3,900
Weighted average remaining service period of nonvested awards	1 year 11 months
Vesting term	5 years
Total intrinsic value of vested RSU's	$ 1,800	$ 2,000	$ 1,600
Performance-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 400
Weighted average remaining service period of nonvested awards	1 year 9 months 18 days

Number of shares issued in settlement of stock option.

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Number of stock options settled for fully vested shares.

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shares represents outstanding awards under the plans.

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Aggregate number of common shares reserved for future issuance.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Unrecognized cost of unvested share-based compensation awards.

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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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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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

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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.

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