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Stock-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Outstanding, beginning of period (in shares)	327,270	350,186	414,769
Granted (in shares)	0	32,750	0
Exercised (in shares)	(38,250)	(55,666)	(62,083)
Canceled/Forfeited (in shares)	(5,334)		(2,500)
Outstanding, end of period (in shares)	283,686	327,270	350,186	414,769
Exercisable (in shares)	262,821
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 20.21	$ 19.45	$ 19.07
Granted (in dollars per share)	0	28.15	0
Exercised (in dollars per share)	17.19	20.12	16.79
Canceled/Forfeited, weighted average exercise price (in dollars per share)	24.02		22.90
Outstanding, end of period (in dollars per share)	20.46	$ 20.21	$ 19.45	$ 19.07
Exercisable (in dollars per share)	$ 19.85
Weighted Average Remaining Contractual Life (years)
Outstanding, weighted average remaining contractual life	3 years 6 months 29 days	4 years 3 months 10 days	4 years 3 months	5 years 29 days
Exercisable, weighted average remaining contractual life	3 years 2 months 19 days
Aggregate Intrinsic Value
Outstanding, aggregate intrinsic value	$ 434	$ 2,255	$ 4,453	$ 1,814
Exercised, aggregate intrinsic value	216	$ 446	625
Canceled/Forfeited, aggregate intrinsic value	0		$ 0
Exercisable, aggregate intrinsic value	$ 434

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Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Canceled Or Forfeited In Period, Intrinsic Value

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Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Remaining Contractual Term [Abstract]

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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.

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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.

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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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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.

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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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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 per share amount at which grantees can acquire shares of common stock by exercise of options.

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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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