Stock Based Compensation (Details) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock based compensation:
Employee Service Shared-based Compensation, Tax Benefit from Compensation Expense, Restricted Stock	$ 126,000
2006 Plan
Stock based compensation:
Number of shares authorized for grant	3,000,000
Shares Remaining for Issuance	1,369,528
Restricted Stock [Member]
Stock based compensation:
Employee Service Shared-based Compensation, Tax Benefit from Compensation Expense, Restricted Stock			$ 202,000
Restricted stock, nonvested:
Restricted stock, nonvested, beginning of year (in shares)	158,261	112,907	104,068
Restricted stock, grants in period (in shares)	84,643	122,963	56,662
Restricted stock, vested in period (in shares)	(95,717)	(49,183)	(46,629)
Restricted stock, forfeitures in period (in shares)	(6,092)	(28,426)	(1,194)
Restricted stock, nonvested, end of year (in shares)	141,095	158,261	112,907
Restricted stock, weighted average grant date fair value:
Restricted stock, nonvested, weighted average grant date fair value, beginning of period (USD per share)	$ 14.55	$ 16.86	$ 10.79
Restricted stock, grants in period, weighted average grant date fair value (USD per share)	19.17	12.59	24.39
Restricted stock, vested in period, weighted average grant date fair value (USD per share)	15.25	14.16	11.82
Restricted stock, forfeitures in period, weighted average grant date fair value (USD per share)	17.93	15.93	24.39
Restricted stock, nonvested, weighted average grant date fair value, end of period (USD per share)	$ 16.79	$ 14.55	$ 16.86
Total unrecognized compensation expense	$ 1,601,000	$ 1,356,000
Weighted average period for recognition of compensation expense	1 year 6 months
Shares Paid for Tax Withholding for Share Based Compensation	19,533	10,590	12,141
Restricted Stock [Member] \| 2006 Plan
Stock based compensation:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock [Member] \| Selling, General and Administrative Expenses [Member]
Stock based compensation:
Stock based compensation expense	$ 1,331,000	$ 1,003,000	$ 785,000
Equity [Member]
Stock based compensation:
Employee Service Shared-based Compensation, Tax Benefit from Compensation Expense, Restricted Stock		$ (16,000)	$ 211,000

Employee Service Shared-based Compensation, Tax Benefit from Compensation Expense, Restricted Stock

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- Definition

Shares Remaining for Issuance

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

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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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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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 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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- Definition

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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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- Definition

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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- Definition

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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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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- Definition

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

+ References

No definition available.

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