Stock-Based Compensation (Details) (Stock Option Plan [Member], USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Stock Option Plan [Member]
Summary the stock option transactions
Number of Options Outstanding	213,170
Number of Options Exercised	(385)
Number of Options Outstanding	212,785	213,170
Number of Options Vested and Exercisable	212,785
Weighted Average Exercise Price, Outstanding	$ 31.79
Weighted Average Exercise Price, Exercised	$ 27.24
Weighted Average Exercise Price, Outstanding	$ 31.8	$ 31.79
Weighted Average Exercise Price Vested and Exercisable	$ 31.8
Weighted Average Remaining Contractual Term (Years)	9 months 18 days	1 year 2 months 12 days
Weighted Average Remaining Contractual Term (Years) Vested and Exercisable	9 months 18 days
Aggregate Intrinsic Value Outstanding	$ 2,519,147
Aggregate Intrinsic Value Outstanding	2,710,460	2,519,147
Aggregate Intrinsic Value Vested and Exercisable	$ 2,710,460

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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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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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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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 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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The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

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

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

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