Stock-Based Compensation (Details 1) (USD $)	3 Months Ended
Mar. 31, 2013
Stock option activity
Number of options, Beginning balance	447,359
Number of options, Granted
Number of options, Exercised
Number of options, Cancelled	(3,433)
Number of options, Ending balance	443,926
Weighted-Average Exercise Price
Weighted-average exercise price per share, Beginning balance	$ 19.59
Weighted-average exercise price per share, Granted
Weighted-average exercise price, Exercised
Weighted-average exercise price, Cancelled	$ 4.40
Weighted-average exercise price per share, Ending balance	$ 19.70

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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.

+ References

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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 that were terminated.

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Weighted average price at which grantees can acquire the shares reserved for issuance on stock options awarded.

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

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