Summary of Stock Option Activity and Related Information (Detail) (USD $)	9 Months Ended
Sep. 30, 2012
Number of Shares
Number of shares outstanding at beginning of period	3,991,139
Granted	244,000
Exercised
Forfeited/Canceled	(601,361)
Number of shares outstanding at end of period	3,633,778
Weighted- Average Exercise Price
Weighted- Average Exercise Price outstanding at beginning of period	$ 7.12
Granted	$ 1.57
Exercised
Forfeited/Canceled	$ 9.03
Weighted- Average Exercise Price outstanding at end of period	$ 6.44

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

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