Share-Based Compensation Expense (Schedule of stock option activity)(Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Share-Based Compensation Expense
Number of Shares, Oustanding Options Beginning	1,035
Number of Shares, Stock options, Grants	144
Number of shares, Stock options, Exercised	(234)
Number of shares, Stock options, Forfeitures	(81)
Number of Shares, Outstanding Options, Ending	864
Number of shares, Exercisable Stock Options Outstanding	511
Weighted Average Exercise Price, Options Outstanding, Beginning	$ 11.97
Weighted Average Exercise Price, Options Granted	$ 13.35
Weighted Average Exercise Price, Options Exercised	$ 6.15
Weighted Average Exercise Price, Options Forfeited	$ 19.41
Weighted Average Exercise Price, Outstanding Options, Ending	$ 13.08
Weighted Average Exercise Price, Exercisable	$ 13.79

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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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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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Net 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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