Outstanding Warrants to Purchase Shares of Common Stock (Detail)			6 Months Ended
Jun. 30, 2013	Jun. 11, 2013	Jun. 30, 2013 Warrant 1	Jun. 30, 2013 Warrant 2
Class of Warrant or Right [Line Items]
Offering Date			2009-05	2010-02
Outstanding Warrants	1,131,539		711,539	420,000
Exercise Price		20.16	8.58	27.50
Expiration Date			5/29/2014	2/1/2015
Status			Exercisable	Exercisable

Exercise price per share or per unit of warrants or rights outstanding.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i)(4))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Subparagraph 4

-Article 4

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant