Equity-Based Compensation Plans (Details 1) (Employee Stock Option [Member], USD $)	9 Months Ended
Sep. 30, 2013
Employee Stock Option [Member]
Summary of stock option activity
Number of options, Beginning balance	3,752,418
Weighted Average Exercise Price, Beginning balance	$ 15.99
Number of Options, Granted	642,700
Weighted Average Exercise Price, Granted	$ 10.74
Number of Options, Exercised	(72,454)
Weighted Average Exercise Price, Exercised	$ 5.36
Number of Options, Cancelled	(105,909)
Weighted Average Exercise Price, Cancelled	$ 20.17
Number of options, Ending balance	4,216,755
Weighted Average Exercise Price, Ending balance	$ 15.27
Weighted Average Remaining Contractual Life-Years	4 years 6 months
Aggregate intrinsic value, Ending balance	$ 8,255,665
Number of Options, Exercisable options	2,586,969
Weighted Average Exercise Price, Exercisable options	$ 19.16
Weighted Average Remaining Contractual Term, Exercisable options	3 years 11 months
Aggregate Intrinsic Value, Exercisable options	$ 2,044,688

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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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-Subparagraph (c)(1)(iii)

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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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For presentations that combine terminations, 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 or that expired.

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Weighted average price of options that were either forfeited or expired.

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Gross number of share options (or share units) granted during the period.

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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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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 per share amount at which grantees can acquire shares of common stock by exercise of options.

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

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