Commitments and Contingencies - Additional Information (Detail) (USD $)		1 Months Ended	6 Months Ended
Dec. 31, 2011	Aug. 31, 2011 Redwood City, California [Member] sqft	Jun. 30, 2014 Redwood City, California [Member]	Jun. 30, 2014 Menlo Park, California [Member] sqft
Operating Leased Assets [Line Items]
Operating facility lease area		5,740		12,943
Operating facility lease term			30 months	39 months
Operating facility lease term commencement date			2011-10-16
Security deposit	$ 55,000
Total obligation under lease				$ 1,600,000

The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8,17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_SecurityDeposit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant