Summary of Stock Option Activity (Detail) (USD $)	6 Months Ended
Jun. 30, 2012
Shares
Outstanding, December 31, 2011	3,091,474
Granted	480,000
Exercised	(51,830)
Options forfeited/cancelled	(228,014)
Outstanding, June 30, 2012	3,291,630
Weighted Average Exercise Price
Outstanding, December 31, 2011	$ 6.83
Granted	$ 2.08
Exercised	$ 2.31
Options forfeited/cancelled	$ 7.65
Outstanding, June 30, 2012	$ 6.15

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-Subparagraph (c)(1)(iv)(3)

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-Name Statement of Financial Accounting Standard (FAS)

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Gross 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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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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