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Fair Value Measurement - Schedule of Warrant Liability Measured At Fair Value Using Significant Unobservable Input (Level 3) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Disclosures [Abstract]
Change in fair value of warrant derivative liability	$ (1)	$ 1,366	$ 16
Warrant exercised		$ (1,543)

X

- Definition

Fair value of warrants exercised.

+ References

No definition available.

+ Details

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X

- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 480



-SubTopic 10



-Section 25



-Paragraph 13



-URI http://asc.fasb.org/extlink&oid=6939902&loc=d3e20148-110875



Reference 2: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 230



-SubTopic 10



-Section 45



-Paragraph 28



-Subparagraph (b)



-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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- References

No definition available.

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