Stock-Based Compensation Arrangements (Details 1) (Stock options, USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock options
Number of Options Outstanding
Options outstanding at the beginning of the period (in shares)	949,685	463,023
Granted (in shares)	63,000	494,663
Exercised (in shares)
Cancelled / forfeited (in shares)	(2,387)	(8,001)
Options outstanding at the end of the period (in shares)	1,010,298	949,685	463,023
Unvested at December 31, 2014	402,900
Vested and exercisable at December 31, 2014	607,395
Weighted Average Exercise Price Per Share
Options outstanding at the beginning of the period (in dollars per share)	$ 15.02	$ 26.61
Granted (in dollars per share)	$ 3.11	$ 4.22
Exercised (in dollars per share)
Cancelled / forfeited (in dollars per share)	$ 31.08	$ 18.55
Options outstanding at the end of the period (in dollars per share)	$ 14.24	$ 15.02	$ 26.61
Unvested at the end of the period (in dollars per share)	$ 4.07
Vested and exercisable at the end of the period (in dollars per share)	$ 20.99
Weighted Average Remaining Contractual Term (Years)
Options outstanding	6 years 6 months 29 days	7 years 4 months 17 days	5 years 6 months 29 days
Unvested at the end of the period	8 years 11 months 12 days
Vested and exercisable at the end of the period	5 years
Aggregate Intrinsic Value
Options outstanding		$ 152	$ 347
Unvested at the end of the period
Vested and exercisable at the end of the period

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Represents the amount of difference between fair value of the underlying shares reserved for issuance and exercise price of options unvested.

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As of the balance sheet date, the weighted-average exercise price for unvested stock options.

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Weighted average remaining contractual term for unvested options, 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 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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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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Number of non-vested options outstanding.

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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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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 that were terminated.

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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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