Fair Value Measurement (Details 2) (Warrant liabilities [Member], USD $)	12 Months Ended
Dec. 31, 2012
Warrant liabilities [Member]
Roll forward for liabilities measured at fair value using significant unobservable inputs (Level 3)
Balance at December 31, 2011	$ 6,011,120
Less fair value of warrants exercised	(4,435,957)
Add fair value of warrants issued	1,714,436
Add change in fair value of warrants	5,867,798
Balance at December 31, 2012	$ 9,157,397

This element represents a liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

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=7578670&loc=d3e19207-110258

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