Stockholders' Equity - Summary of Option Activity (Detail) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding at beginning of period	3,196,100
Number of Shares, Exercised	(38,454)
Number of Shares, Forfeitures	(71,237)
Number of Shares, Outstanding at end of period	3,174,102
Weighted Average Exercise Price Per Share, Outstanding at beginning of period	$ 4.32
Weighted average Exercise Price Per Share, Exercised	$ 3.41
Weighted Average Exercise Price Per Share, Forfeitures	$ 10.22
Weighted Average Exercise Price Per Share, Outstanding at end of period	$ 5.39
Aggregate Intrinsic Value, Outstanding at beginning of period		$ 18,025
Others [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted	87,693
Weighted Average Exercise Price Per Share, Granted	$ 13.17

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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.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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

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Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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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 price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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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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