Stock-Based Compensation (Details 4) (USD $)	6 Months Ended
Jun. 30, 2012
Summary of Stock Option Activity
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Beginning Balance	1,411,581
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 9.02
Options Outstanding Granted	4,500
Weighted Average Exercise Price Granted	$ 7.15
Options Outstanding Exercised	(3,719)
Weighted Average Exercise Price Exercised	$ 6.72
Options Outstanding Expired or Cancelled	(216,350)
Weighted Average Exercise Price Expired or Cancelled	$ 8.71
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance	1,196,012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance	$ 9.17
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	1,176,419
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 9.22

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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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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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 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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