Stock-Based Compensation (Details) (Stock Option Plan [Member], USD $)	6 Months Ended	12 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Stock Option Plan [Member]
Summary the stock option transactions
Number of Options Outstanding at begining	260,660
Number of Options Exercised	(5,403)
Number of Options Expired	(15,299)
Number of Options Exercisable	239,958
Number of Options Outstanding at ending	239,958	260,660
Weighted Average Exercise Price, Outstanding at January 1, 2013	$ 34.69
Weighted Average Exercise Price, Exercised	$ 28.22
Weighted Average Exercise Price, Expired	$ 57.66
Weighted Average Exercise Price Outstanding at June 30, 2013	$ 33.67	$ 34.69
Weighted Average Exercise Price Exercisable at June 30, 2013	$ 33.67
Aggregate Intrinsic Value Outstanding at January 1, 2013	$ 1,253,039
Aggregate Intrinsic Value Outstanding at June 30, 2013	3,173,242	1,253,039
Weighted Average Remaining Contractual Term (Years)	2 years 7 months 6 days	3 years
Weighted Average Remaining Contractual Term (Years) Exercisable	2 years 7 months 6 days
Aggregate Intrinsic Value exercisable	$ 3,173,242

The weighted-average period remaining until option expiration pertaining to the outstanding options.

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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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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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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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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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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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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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

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