Share-based Compensation Stock Options (Details) (Stock Options, USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares - Stock options outstanding at January 1, 2012	418
Shares - Exercised	(16)
Shares - Forfeited	(113)
Shares - Expired	(19)
Shares - Stock options exercisable at December 31, 2012	270
Shares - Stock options exercisable at December 31, 2012	111
Shares - Stock options vested or expected to vest as of December 31, 2012	259
Weighted Average Exercise Price - Stock options outstanding at January 1, 2012	$ 12.44
Weighted Average Exercise Price - Exercised	$ 9.11
Weighted Average Exercise Price - Forfeited	$ 15.56
Weighted Average Exercise Price - Expired	$ 12.60
Weighted Average Exercise Price - Stock options outstanding at December 31, 2012	$ 11.34
Weighted Average Exercise Price - Stock options exercisable at December 31, 2012	$ 9.25
Weighted Average Exercise Price - Stock options vested or expected to vest as of December 31, 2012	$ 11.28
Intrinsic Value - Stock options outstanding at December 31, 2012	$ 937
Intrinsic Value - Stock options exercisable at December 31, 2012	621
Intrinsic Value - Stock options vested or expected to vest as of December 31, 2012	$ 915
Weighted Average Remaining Contractual Life - Stock options outstanding at December 31, 2012	3 years 9 months 18 days
Weighted Average Remaining Contractual Life - Stock options exercisable at December 31, 2012	1 year 6 months
Weighted Average Remaining Contractual Life - Stock options vested or expected to vest as of December 31, 2012	3 years 8 months 12 days

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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 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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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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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of options outstanding.

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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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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise prices of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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

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