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Vesting percentage of equity based compensation awards during specified period.

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Vesting percentage of equity based compensation awards each on first and second anniversary of the grant.

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Vesting percentage of equity based compensation awards on third anniversary of the grant.

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Share-based Compensation Arrangement by Share-based Payment Award, Number of Plans

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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 awards, other than options, awarded to employees as compensation.

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Unrecognized cost of unvested options awarded to employees as compensation.

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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 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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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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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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Percentage of vesting of share-based compensation awards.

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

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Share-Based Compensation Plan - Narrative (Details)	12 Months Ended
Share-Based Compensation Plan - Narrative (Details)	Dec. 31, 2016 USD ($) director share_based_compensation_plan shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans \| share_based_compensation_plan	1
Share based compensation expense \| $	$ 925,000	$ 605,000	$ 426,000
Total income tax benefit related to share-based compensation \| $	5,000	$ 117,000	$ 63,000
Unrecognized compensation expense related to nonvested stock options awards \| $	$ 0
Options granted (in shares)	0	0	0
Aggregate intrinsic value of options exercised \| $	$ 88,000		$ 126,500
Exercise of stock options (in shares)	6,650	0	25,501
Aggregate intrinsic value of options outstanding \| $	$ 484,800	$ 134,500	$ 120,300
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service-based award vesting percentage	50.00%
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Options vesting percentage each on first and second anniversary	25.00%
Options vesting percentage on third anniversary	50.00%
2006 Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	430,000
2006 Equity Compensation Plan [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	49,100
2006 Equity Compensation Plan [Member] \| Performance Based Restricted Stock [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	31,750
2006 Equity Compensation Plan [Member] \| Time Based Restricted Stock [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	17,350
2006 Equity Compensation Plan [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	53,500	36,150	41,533
Restricted stock nonvested outstanding, Weighted average remaining contractual terms	2 years 6 months	2 years 8 months 12 days	3 years 6 months
Unrecognized compensation expense related to nonvested restricted stock awards \| $	$ 1,600,000
2006 Equity Compensation Plan [Member] \| Restricted Stock [Member] \| Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	4,400
Number of directors \| director	11
Shares of restricted stock per director	400
Vesting percent (as a percent)	100.00%