Changes in Fair Value of Financial Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013 Warrant Liability	Jun. 30, 2013 Debt Redemption Features	Dec. 31, 2012 Debt Redemption Features
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 2,935	$ 848	$ 848
Unrealized gain	(1,497)
Ending balance	$ 1,438	$ 848	$ 848

Amount of gain (loss) recognized on the income statement for 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)(1)

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

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration