Balance Sheet Components - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Balance Sheet Related Disclosures [Abstract]
Intangible assets-license cost	$ 500	$ 500	$ 500
Accumulated amortization	(319)	(236)	(69)
Intangible assets, net	$ 181	$ 264	$ 431

No definition available.

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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