Stock Compensation (Details) (USD $)	6 Months Ended
Jun. 30, 2012
Summary of Company's stock option activity
Number of shares, Outstanding at January 1, 2012	270,634
Number of shares, Granted
Number of shares, Exercised
Number of shares, Forfeited
Number of shares, Expired	(49,451)
Number of shares, Outstanding at June 30, 2012	221,183
Number of shares, Exercisable at June 30, 2012	197,928
Weighted Average Exercise Price, Outstanding at January 1, 2012	$ 23.51
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Exercised
Weighted Average Exercise Price, Forfeited
Weighted Average Exercise Price, Expired	$ 18.19
Weighted Average Exercise Price, Outstanding at June 30, 2012	$ 24.70
Weighted Average Exercise Price, Exercisable at June 30,2012	$ 24.97
Weighted Average Contractual Term (in years), Outstanding at June 30, 2012	3 years 6 months
Weighted Average Contractual Term (in years), Exercisable at June 30, 2012	3 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding at June 30, 2012,
Aggregate Intrinsic Value, Exercisable at June 30, 2012,

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 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 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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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including 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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