Fair Value Measurements (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Liabilities [Abstract]
Fair value of loan	$ 23,600,000	$ 0
Long-Term Debt	18,354,000	0
Recurring [Member]
Assets [Abstract]
Fair Value	86,608,000	27,292,000
Recurring [Member] \| Level 1 [Member]
Assets [Abstract]
Fair Value	86,608,000	27,292,000
Recurring [Member] \| Level 2 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Level 3 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Cash and cash equivalents [Member]
Assets [Abstract]
Fair Value	86,283,000	26,892,000
Recurring [Member] \| Cash and cash equivalents [Member] \| Level 1 [Member]
Assets [Abstract]
Fair Value	86,283,000	26,892,000
Recurring [Member] \| Cash and cash equivalents [Member] \| Level 2 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Cash and cash equivalents [Member] \| Level 3 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Certificate of Deposit [Member]
Assets [Abstract]
Fair Value	325,000	400,000
Recurring [Member] \| Certificate of Deposit [Member] \| Level 1 [Member]
Assets [Abstract]
Fair Value	325,000	400,000
Recurring [Member] \| Certificate of Deposit [Member] \| Level 2 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Certificate of Deposit [Member] \| Level 3 [Member]
Assets [Abstract]
Fair Value	0	0
Recurring [Member] \| Common Stock Warrant [Member]
Liabilities [Abstract]
Fair Value	5,425,000	6,305,000
Recurring [Member] \| Common Stock Warrant [Member] \| Level 1 [Member]
Liabilities [Abstract]
Fair Value	0	0
Recurring [Member] \| Common Stock Warrant [Member] \| Level 2 [Member]
Liabilities [Abstract]
Fair Value	0	0
Recurring [Member] \| Common Stock Warrant [Member] \| Level 3 [Member]
Liabilities [Abstract]
Fair Value	$ 5,425,000	$ 6,305,000

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

+ Details

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

- Details

Name:	us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

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