Stock-based Compensation (Stock Option Activity) (Details) $ / shares in Units, $ in Thousands	6 Months Ended
Jun. 30, 2018 USD ($) $ / shares shares
Stock-based Compensation [Abstract]
Outstanding, Number of Options \| shares	159,807
Outstanding, Weighted-Average Exercise Price \| $ / shares	$ 11.35
Exercised, Number of Options \| shares	(15,518)
Exercised, Weighted-Average Exercise Price \| $ / shares	$ 9.85
Forfeited or expired, Number of Options \| shares
Forfeited or expired, Weighted-Average Exercise Price \| $ / shares
Outstanding, Number of Options \| shares	144,289
Outstanding, Weighted-Average Exercise Price \| $ / shares	$ 11.51
Outstanding, Weighted-Average Remaining Contractual Term	1 year 4 months 13 days
Outstanding, Aggregate Intrinsic Value \| $	$ 1,925
Exercisable, Number of Options \| shares	143,989
Exercisable, Weighted-Average Exercise Price \| $ / shares	$ 11.50
Exercisable, Weighted-Average Remaining Contractual Term	1 year 4 months 10 days
Exercisable, Aggregate Intrinsic Value \| $	$ 1,922

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ 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 (c)(1)(iii)
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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

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-Publisher FASB
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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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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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

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