Fair Value of Financial Instruments - Summary of Changes in Fair Value of Company's Preferred Stock Warrant Liability (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Calculation [Roll Forward]
Beginning balance	$ 297
Change in fair value	(50)
Reclassification to additional paid-in capital	(247)
Ending balance	$ 0

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant