Warrants Outstanding (Detail) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Class of Warrant or Right [Line Items]
Number of Shares Outstanding Under Warrant	3,966
Issue Date May 2006
Class of Warrant or Right [Line Items]
Warrants, Term (Years)	7 years
Warrants, Exercise Price per Share	9.03
Number of Shares Outstanding Under Warrant	106
Issue Date August 2010
Class of Warrant or Right [Line Items]
Warrants, Term (Years)	5 years
Warrants, Exercise Price per Share	1.50
Number of Shares Outstanding Under Warrant	3,860

Aggregate amount of each class of warrants or rights outstanding.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Article 4

Name:	us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant